Method for removing cations and anions from an engine coolant liquid

ABSTRACT

An apparatus and method for removing particulates, hydrcarbons (such as oil), cations and anions including nitrite ions from a liquid, such as an engine coolant liquid having a freezing point depressant and situated in an internal combination engine cooling system. The apparatus has at least one filter for removing particulates and hydrocarbons; a strong acid cation exchange bed in the hydrogen form for removing cations; a strong base anion exchange bed in the hydroxide form for removing anions; and separator for separating gas containing nitrogen, such as nitric oxide and/or nitrogen dioxide, that is produced in the cation exchange bed and/or the anion exchange bed. The method for removing particulates, hydrocarbons, cations, anions and nitrite ions from an engine coolant liquid having a freezing point depressant comprises providing an engine coolant liquid having particulates, hydrocarbons, cations, anions and nitrite ions; passing the engine coolant liquid through a zone for filtering wherein particulates and hydrocarbons are removed from the engine coolant liquid; and passing the engine coolant liquid through a strong acid cation exchanger bed in the hydrogen form wherein cations are removed from the engine coolant liquid and nitrite ions are converted into nitric oxide and/or nitrogen dioxide. The method further comprises passing the engine coolant liquid through a strong base anion exchanger bed in the hydroxide form wherein anions are removed from the engine coolant liquid; and subsequently separating the nitric oxide and/or nitrogen dioxide from the engine coolant liquid to produce an engine coolant liquid having the freezing point depressant.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is related to an apparatus and method for removingparticulates, ions and impurities from an engine coolant liquid. Morespecifically, this invention provides for an apparatus and method forremoving particulates, impurities, and cations and anions from an enginecoolant liquid having a freezing point depressant and situated in aninternal combustion engine cooling system.

2. Description of the Prior Art

One of the biggest problems facing today's automotive and industrialshops is the disposal of hazardous waste. On Oct. 17, 1986 SARA TitleIII was signed into law by the U.S. Congress. Section 313 of thislegislation designated ethylene glycol, the major component inantifreeze, as a toxic chemical. Furthermore, the EPA designatesethylene glycol as hazardous waste under 40 CFR 414.60. The regulatoryimpact on automotive service stations and other industrial shops woulddepend on the volume of antifreeze to be disposed of and other factors,especially when spent antifreeze has to be periodically replaced.Presently, there are but two viable options or alternatives fordiscarding spent antifreeze; namely, collect and store it in drumsand/or pay a hazardous waste collector to transport it for disposal.Both of these options or alternatives are costly, especially whencompared to disposing the spent antifreeze illegally by merely pouringit down the drain.

Antifreeze is a rather complex mixture of chemical components designedto perform the following functions in a vehicle:

(a) protect against overheating and freezing;

(b) protect the many dissimilar metals within the cooling system(copper, brass, steel, iron, aluminum and lead) from corrosion;

(c) buffer against acidic contamination (blow by gases, glycoldegredation products);

(d) prevent foaming;

(e) prevent hard water scaling;

(f) reduce consequences of oil fouling; and

(g) protect diesel wet-sleeve liners from cavitation damage.

All of those functions are important and demanding on an engine liquidcoolant. Each must be specifically considered or, at some point, enginedamage will occur, resulting in sometimes costly repair. To obtain theoptimum protection, the engine liquid coolant must have a well balancedadditive package that may consist of up to 15 different inhibitors inaddition to the more commonly known components such as water, ethyleneglycol, and dye. Most inhibitors are introduced as sodium or potassiumsalts and usually are specific in providing corrosion inhibition to oneor two metals. As antifreeze ages and accumulates miles or hours in avehicle's cooling system, it also accumulates many different types ofcontaminants. These include oil from leaking oil coolers and water pumplubricants, corrosion products in the form of metal ions and metalhydroxides (e.g. aluminum hydroxide can be produced through aluminumcylinder head corrosion), and acids from blowby gasses and glycoldegredation products such as glycolic, formic, oxalic, acetic acid.Other impurities may be present in the water used to dilute theantifreeze concentrate. These are ions, more commonly known as"minerals", and they include chlorides, sulfates, carbonates, and metalcations such as calcium and magnesium. Chlorides and sulfates arecorrosive, and calcium and magnesium cause scaling. In areas with verypoor water quality, trace amounts of metals may also be present,especially iron and lead.

There are a number of conventional processes available for purifyingand/or recycling antifreeze that has been contaminated. The most commonconventional type of process available at present is based on a simplefiltration method. The used antifreeze coolant is collected, pured intoa filtration unit, filtered through a paper filter of varyingporosities, discharged back into the vehicle, and then treated with aconcentrated additive package to restore the inhibitor level. In thisprocess, although the antifreeze has been "recycled" it has not beenpurified to any degree. It may appear cleaner as the filter will removeoil and solid contaminants large enough to be trapped by the filterwhich will improve its clarity, but the ionic species such as theimpurities in the water, the acids, and the free metals will not havebeen removed and will be recycled back into the vehicle cooling system.Another conventional filtering process utilizes diatomaceous earth asthe filtering medium. A diatomaceous earth filtering medium has agreater surface filtering area than a paper filter. This method is atleast slightly more effective than paper or composition filtration, butthe bulk of the impurities are still put back into the vehicle coolingsystem.

A problem with both of these conventional filtering processes is thelack of control over the inhibitor level in the final coolant solution.Both rely on adding a concentrated additive package to the system afterthe filtration step. Thus, the old additives retained in the filteredcoolant plus the addition of concentrated inhibitors may lead to seriousoverconcentration. This may result in the precipitating or otherwisecoming out of solution to deposit in cool, low lying areas of thevehicle cooling system, thus reducing flow and overall efficiency. Theymay also cause seal leaks such as in the water pump or plug filters indiesel cooling systems.

Another conventional approach to recycling antifreeze is thedistillation process, which is one of the oldest chemical purificationprocesses known. It is truly a "purification" process, unlike thefiltration method, because it physically separates the water and glycolfrom all additives, impurities, contaminants, and even the dye. Thereare two ways of performing a distillation; namely, by the flashdistillation process or by the simple distillation process.

The flash distillation process is a process in which the used antifreezeis added to a vessel preheated to a temperature above the boiling pointof water and the glycol constituents. This essentially vaporizes thewater and glycol and it is then condensed from a gaseous form back intoa liquid. Non-volatile impurities are left behind in the distillationvessel. The condensate or distillate can then be checked for a glycoland inhibitor level and restored to a "recycled" condition. Theadvantage to this method is that it is much more effective than thesimple filtration method at removing all of the contaminants, includingionic species.

The simple distillation process is very similar to the flash method withrespect to the equipment employed. However, the used antifreeze ispoured into the distillation chamber and then heat is applied slowly.This produces a boiling point range in which water will come off firstto be collected separately, with the glycol boiling off second. If thereare appreciable quantities of other glycols besides ethylene such aspropylene, triethylene, or tetraethylene, the boiling point range of theantifreeze will be quite wide in terms of temperature. The simpledistillation method is perhaps the slowest and most time consuming ofthe conventional processes but it is highly effective at removingimpurities and providing pure water and glycol. It also formulates thewaste into a solid form that is much less expensive to dispose of thandrums of used antifreeze. The distilled water can also be used for otherpurposes, such as water for a car wash unit or battery water. Theprocess does require operator manipulation and monitoring to determinewhen all of the water has all been condensed and when the glycol beginsto distill.

Thus, what is needed and what has been invented by us is a fast,economical and ecologically advantageous method and apparatus forremoving particulates and ions (i.e., cations and anions) from a liquid,such as the engine coolant liquid from the cooling system of a vehicle.

SUMMARY OF THE INVENTION

The present invention broadly accomplishes its desired objects bybroadly providing an apparatus and method for removing essentially allimpurities including particulates and ions, such as cations and anions,from a liquid, such as an engine coolant liquid emanating from thecooling system of a vehicle. The apparatus broadly comprises a means forpassing a liquid having ions, including nitrogen containing ions andsuch as nitrate and nitrite ions, through at least one ion-exchanger bedwherein at least part of the ions are removed and at least part of thenitrogen containing ions is converted into nitrogen containing compounds(e.g. nitrous acid and gas containing nitrogen, such as nitric oxide,nitrogen dioxide, and mixtures thereof) to produce a liquid with atleast part of the ions removed and having the nitrogen containingcompounds. The apparatus also comprises a means, communicatively engagedto and with the ion exchanger bed, for removing the nitrogen containingcompounds from the liquid to produce a liquid having at least part ofthe ions removed and at least part of the nitrogen containing compoundsremoved. The method for removing ions from liquid broadly comprises thesteps of:

(a) passing a liquid having ions, including nitrogen containing ions,through an ion-exchanger bed wherein at least part of the ions areremoved and at least part of the nitrogen containing ions is convertedinto nitrogen containing compounds to produce a liquid with at leastpart of the ions removed and having nitrogen containing compounds; and

(b) passing the produced liquid of step (a) through a means for removingnitrogen containing compounds to produce a liquid with at least part ofthe ions removed and with at least part of the nitrogen containingcompounds removed.

The present invention further accomplishes its desired objects byfurther broadly providing an apparatus and method for treating andremoving particulates, ions, and nitrite ions from an engine coolantliquid and situated in a cooling system of an internal combustion enginecomprising (a) a means for removing from a cooling system of an internalcombustion engine an engine coolant liquid which is situated in thecooling system of the internal combustion engine and containsparticulates, ions, and nitrite ions; (b) a means, in communication withthe means for removing an engine coolant liquid, for removingparticulates from the engine coolant liquid containing particulates,ions, and nitrite ions; (c) a means, in communication with the means forremoving particulates from the engine coolant liquid, for removing ionsfrom the engine coolant liquid containing ions and wherein nitrite ionsare converted into gaseous nitrogen containing compounds such asnitrogen oxides; (d) a means, in communication with the means forremoving ions from the engine coolant liquid, for removing the nitrogencontaining compounds from the engine coolant liquid containing thegaseous nitrogen containing compounds; and (e) a means, in communicationwith the means for removing the gaseous nitrogen containing compounds,for returning the engine coolant liquid to the cooling system of theinternal combustion engine. The method for treating and removingparticulates, ions, and a nitrogen containing compound from an enginecoolant liquid situated in a cooling system of an internal combustionengine broadly comprises the steps of:

(a) removing, from a cooling system of an internal combustion engine tothe exterior thereof, an engine coolant liquid which is situated in thecooling system of the internal combustion engine and containsparticulates, ions, and nitrite ions;

(b) passing the engine coolant liquid through a filtration zone whereina majority of the particulates are removed to produce an engine coolantliquid having the ions and the nitrite ions;

(c) passing the produced engine coolant liquid of step (b) through ameans for removing ions wherein at least part of the ions is removed andnitrite ions are converted into nitrogen containing compounds such asnitrogen oxides, to produce a liquid containing the nitrogen containingcompounds;

(d) passing the produced engine coolant liquid of step (c) through ameans for removing the nitrogen containing compounds wherein at leastpart of the nitrogen containing compounds is removed; and

(e) returning subsequently the engine coolant liquid, produced from themeans for removing the nitrogen containing compounds, to the coolingsystem of the internal combustion engine.

The present invention still yet further accomplishes its desired objectsby more particularly providing an apparatus and method for removingparticulates, hydrocarbons (such as oils), cations, anions, and nitriteions from an engine coolant liquid having a freezing point depressant.The apparatus more particularly comprises (a) a first mechanicalfiltering system wherein part of the particulates are removed from theengine coolant liquid to produce an engine coolant liquid havingresidual particulates, hydrocarbons (such as oils), cations, anions,nitrite ions and the freezing point depressant; (b) a pump means forpumping the engine coolant liquid received from the first mechanicalfiltering system down line towards a chemical filtering means forfiltering and wherein at least part of the hydrocarbons (such as oils)is to be removed; (c) a chemical filtering means which receives enginecoolant liquid from the pump means and filters out or removes at leastpart of the hydrocarbons (such as oils) from the engine coolant liquidto produce an engine coolant liquid having residual particulates,cations, anions, nitrite ions and the freezing point depressant; (d) asecond mechanical filtering means which receives engine coolant liquidfrom the chemical filtering means and filters out or removes at leastpart of the residual particulates to produce an engine coolant liquidhaving cations, anions, nitrite ions, and the freezing point depressant;(e) a strong acid cation exchange bed in the hydrogen form for receivingengine coolant liquid from the second mechanical filtering means andremoving at least part of the cations and for converting the nitriteions into a gas containing nitrogen selected from the group consistingof nitric oxide, nitrogen dioxide, and mixtures thereof, to produce anengine coolant liquid having anions, the gas containing nitrogen, andthe freezing point depressant; (f) a strong base anion exchange bed inthe hydroxide form wherein at least part of the anions is removed toproduce an engine coolant liquid having the gas containing nitrogen andthe freezing point depressant; and (g) an activated particulate carbonbed for receiving the engine coolant liquid from the anion exchange bedand for removing or separating out at least part of the gas containingnitrogen to produce an engine coolant liquid having the freezing pointdepressant. The method for removing particulates, hydrocarbons (such asoils), cations, anions and nitrite ions from an engine coolant liquidhaving a freezing point depressant comprises the steps of:

(a) providing an engine coolant liquid having particulates,hydrocarbons, cations, anions and nitrite ions, and a freezing pointdepressant;

(b) passing the engine coolant liquid of step (a) through a firstmechanical filtering means for filtering and wherein part of theparticulates are removed to produce an engine coolant liquid havingresidual particulates, hydrocarbons, cations, anions, nitrite ions, andthe freezing point depressant;

(c) passing the produced engine coolant liquid of step (b) through azone for pumping wherein the produced engine coolant liquid of step (b)is pumped towards a chemical filtering means for filtering and whereinat least part of the hydrocarbons is to be removed;

(d) passing the pumped engine coolant liquid of step (c) through achemical filtering means for filtering and wherein at least part of thehydrocarbons is removed to produce an engine coolant liquid havingresidual particulates, cations, anions, nitrite ions and the freezingpoint depressant;

(e) passing the produced engine coolant liquid of step (d) through asecond mechanical filtering means for filtering and wherein at leastpart of the residual particulates is removed to produce an enginecoolant liquid having cations, anions, nitrite ions, and the freezingpoint depressant;

(f) passing the produced engine coolant liquid of step (e) through astrong acid cation exchange bed in the hydrogen form wherein at leastpart of the cations is removed and at least part of the nitrite ions isconverted into a gas containing nitrogen and selected from the groupconsisting of nitric oxide, nitrogen dioxide, and mixtures thereof, toproduce an engine coolant liquid having anions, the gas containingnitrogen, and the freezing point depressant;

(g) passing the produced engine coolant liquid of step (f) through astrong base anion exchange bed in the hydroxide form wherein at leastpart of the anions is removed to produce an engine coolant liquid havingthe gas containing nitrogen and the freezing point depressant; and

(h) passing the produced engine coolant liquid of step (g) through a bedof activated particulate carbon wherein at least part of the gascontaining nitrogen is removed to produce an engine coolant liquidhaving the freezing point depressant.

It is therefore an object of the present invention to provide anapparatus for removing particulates, hydrocarbons (such as oils and thelike), cations, anions, and nitrite ions from a liquid, such as anengine coolant liquid, preferably having a freezing point depressant.

It is another object of the present invention to provide a method forremoving particulates, hydrocarbons (such as oils and the like),cations, anions, and nitrite ions from a liquid, such as an enginecoolant liquid, preferably having a freezing point depressant.

These, together with the various ancillary objects and features whichwill become apparent to those skilled in the art as the followingdescription proceeds, are attained by this novel apparatus and method, apreferred embodiment being shown with reference to the accompanyingdrawings, by way of example only, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the cabinet containing the apparatus ofthe present invention;

FIG. 2 is a front elevational view of the cabinet in FIG. 1;

FIG. 3 is a rear elevational view of the cabinet in FIG. 1;

FIG. 4 is a perspective segmented view of the cabinet of FIG. 1 withoutthe apparatus of the present invention;

FIG. 5 is a partial perspective view of the female receiving end of thefasteners for the front and rear doors of the cabinet in FIG. 1;

FIG. 6 is a partial perspective view of the male end of the fastenersfor the front and rear doors of the cabinet in FIG. 1;

FIG. 7 is an end elevational view of the cabinet of FIG. 1 with thefront door shown to be swinging open as a dotted line representation;

FIG. 8 is a vertical sectional view taken in direction of the arrows andalong the plane of line 8--8 in FIG. 7;

FIG. 9 is a horizontal sectional view taken in direction of the arrowsand along the plane of line 9--9 in FIG. 8;

FIG. 10 is a segmented perspective view disclosing a T-fitting wherein aconductivity probe is housed for contacting engine coolant liquid suchthat its resistance and/or conductivity can be gauged and monitored;

FIG. 11 is a top plan view of the three (3) in line filters disposed inseries;

FIG. 12 is a horizontal sectional view taken in direction of the arrowsand along the plane of line 12--12 in FIG. 8;

FIG. 13 is a rear elevational view of the cabinet with the rear doorhaving been removed to expose the two ion exchange containers in therear of the apparatus of the present invention;

FIG. 14 is side elevational view of one of the ion exchange containerswith the insides partially exposed to show the ion exchange resins;

FIG. 15 is a partial view of a segment of the outlet conduct havingsensors to detect the resistance and/or conductivity of the enginecoolant liquid, and further having the electronic check valve;

FIG. 16 is a perspective view of the rack that assists in holding theion exchange containers in place within the cabinet;

FIG. 17 is a side elevational view of the three in line filters with theinsides partial shown to expose the inside of each filter;

FIG. 18 is a segmented perspective view of one of the mechanical filtersshowing the filter container, the spun filter and the top which is to bethreadably engaged to the threaded neck of the filter container;

FIG. 19 is a full schematic view of one embodiment of the presentinvention;

FIG. 20 is an electrical schematic diagram for one embodiment of thepresent invention wherein the power source is a 110 volt power source asopposed to a 12 volt power source (i.e., the battery of a car);

FIG. 21 is a partial schematic view of another embodiment of the presentinvention;

FIG. 22 is a partial schematic view of yet another embodiment of thepresent invention; and

FIG. 23 is a full schematic view of another embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Referring in detail now to the drawings wherein similar parts of theinvention are identified by like reference numerals there is seen anapparatus, generally illustrated as 10, which is for removing cations,anions, hydrocarbons (e.g., oils) and particulate solids from a liquid,preferably an engine coolant liquid which may or may not include afreezing point depressant such as glycols (e.g. ethylene glycol,propylene glycol, etc.). For purposes of describing the presentinvention, the "liquid" will be an engine coolant liquid having afreezing point depressant and termed "engine antifreeze coolant liquid".It should be understood that the spirit and scope of the presentinvention is to include "any liquid" and not be limited to enginecoolant liquid which may or may not include an antifreeze/freezing pointdepressant component. In one preferred embodiment of the presentinvention, the apparatus 10 of this invention may be interposed in anengine antifreeze coolant circuit for continuously filtering particulatesolids and hydrocarbons (oils) from the antifreeze coolant while alsoremoving anions and cations therefrom, including potentially deleteriousnitrite ions. In another preferred embodiment of the present invention,the apparatus 10 may be employed alone and not in communication with anengine antifreeze coolant circuit to treat an engine coolant antifreezeliquid that has been provided in bulk (such as in drums) to removecations, anions, hydrocarbons, and particulate solids from the engineantifreeze coolant liquid. The apparatus 10 of the present inventionalso possesses the capabilities of measuring and indicating theresistance and/or conductivity of the antifreeze coolant as a measure ofthe degree of purification of the antifreeze coolant from contaminatingions and particulates.

The apparatus 10 has a cabinet 12 (see FIG. 1) which includes a frame13, a rear door 14, pivotally secured to the rear of the frame 13, apair of opposed side walls 16--16 connected to the sides of the frame13, and a front door 18 pivotally attached to the front of the frame 13.The cabinet 12 also has a top 20 which defines a slanted face 20F, and afloor 22 upon which a rack 24 is mounted. Both the top 20 and the floor22 connect to the frame 13 to be supported thereby. The cabinet 12 isrotatably supported by casters 24--24 and rear wheels 26--26. Each sidewall 16 has an aperture 16a to provide an opening for receiving a handsuch that the user of the apparatus 10 may readily move the cabinet 12with the aid of the casters 24--24 and the wheels 26--26. The rear door14 has an aperture 14a in the lower end thereof wherethrough a foot of auser may pass and rest upon the floor 22 to provide an additional meansfor readily moving the cabinet 12. When the user inserts a foot throughaperture 14a and further inserts hands through the pair of apertures16a--16a in the pair of opposed sides 16--16, the cabinet 12 may readilybe moved by rolling the same on both the casters 24--24 and the rearwheels 26--26, or by rolling the same on only the two rear wheels26--26, similar to moving a two wheel dolly. To posture the cabinet 12such as to balance and rest upon only the two rear wheels, the user,with a foot resting on the floor 22 through the aperture 14a and withthe hands grasping the pair of opposed sides 16--16 of the cabinet 12through the apertures 16a--16a, leans or pulls the cabinet 12 rearwardlyuntil the casters 24--24 are off the support surface and the entireweight of the apparatus 10 is balanced upon the rear wheels 26--26. Insuch a posture, the cabinet 12 may readily be moved by pushing orpulling until the two rear wheels 26--26 commence rolling.

The rear door 14 and the front door 18 are respectively provided with aplurality of door apertures 14a and 18a wherethrough fasteners 28 (seeFIG. 6) may be inserted to be received by female receiving ends 30 (seeFIG. 5) each of which are spacedly secured along the frame 13 such as toregister with door apertures 14a and 18a. When a fastener 28 is insertedthrough a door aperture 14a and/or 18a and through the female end 30 andturned in a predetermined direction, the rear door 14 and the front door18 are fastened against the frame 13. When all fasteners 28 are rotatedin the opposite direction to the predetermined direction and removedfrom within the female ends 30 and from the door apertures 14a and 18a,the rear door 14 and the front door 18 are both free to be pivotallyopened to expose the remaining parts or elements of the apparatus 10within the cabinet 12.

Exposed through and from various opening in the slanting face 20F of thetop 20 is an on/off switch 32, and a pressure gauge 34 for indicatingwhen the filters (which will be identified below) of the apparatus 10are blocked. When the pressure gauge 34 reads a certain pressure, suchpressure indicates blockage which typically occurs when the filters areplugged and have to be removed or cleaned. A pair of electrical clamps36--36 with respective depending conductors 38--38 pass through the sidewall 16 such as to be freely available to engage a battery 40 (see FIG.20) of a car in order to provide a power source for the electronicelements (e.g. the pump, the sensors, etc.) of the apparatus 10. A pairof indicators 42--42, which may be either lights or meters, are part ofa sensoring system that will be explained in detail below. The sensoringsystem including the indicators 42--42 function to indicate theresistance and/or conductivity of the engine antifreeze coolant liquid.The sensoring system also functions as a determiner as to whether or notan upstream ion exchange zone (which will be identified below) isfunctioning properly and/or has not become exhausted. An exhausted ionexchange zone is no longer capable of effectively removing ions from aliquid, such as the engine antifreeze coolant liquid. As previouslymentioned, one of the capabilities of the apparatus 10 of this inventionis measuring and indicating the resistance and/or conductivity of theengine antifreeze coolant liquid as a measure of the degree ofpurification of the antifreeze coolant from contaminating ions,dissolved solids and particulates. The sensoring system including theindicators 42--42 can be set or calibrated to indicate any predeterminedresistance or conductivity, which is preferably a 20,000 ohms resistanceor a 50 micromhos of conductivity. A resistance greater than 20,000 ohmsor a conductivity of less than 50 micromhos would indicate an acceptablepurification of the engine antifreeze coolant liquid. The higher theresistance of the engine antifreeze coolant liquid, the lesser is theconcentration of contaminating ions, dissolved solids and particles.Similarly, the higher the conductivity of the engine antifreeze coolantliquid, the greater is the concentration of contaminating ions,dissolved solids and particles. Thus, if the indicators 42--42 arelights which are calibrated through and/or in the sensoring system toilluminate when the resistance of the engine antifreeze coolant liquidis of 50 micromhos or greater, when highly contaminated engineantifreeze coolant liquid is passed through the apparatus 10 includingthe sensoring system, the indicators 42--42 will illuminate because theengine antifreeze coolant liquid is contaminated with dissolved ionicsolids and particulates and the like beyond the acceptable level. Whenthe apparatus 10 of this invention has sufficiently purified the engineantifreeze coolant liquid of undesirable ions, dissolved solids andparticulates, the resistance or conductivity of the engine antifreezecoolant liquid will be greater than 20,000 ohms or less than 50micromhos, respectively, and the indicators 42--42 will cease toilluminate, indicating an engine antifreeze coolant liquid that has beensufficiently purified of ions and/or particulates. The indicators 42--42may be a pair of different color lights calibrated through and/or in thesensoring system to disilluminate at diverse resistance levels andconductivity levels for the engine antifreeze coolant liquid. Thus, oneindicator 42 may be a yellow light calibrated through and/or in thesensoring system to disilluminate at 20,000 ohms or greater resistanceor 50 micromhos or less conductivity, and the second indicator light 42may be a red light calibrated through and in the sensoring system todisilluminate at another resistance or conductivity, for example 50,000ohms or greater resistance or 20 micromhos or less conductivity. Whenhighly contaminated engine antifreeze coolant liquid is initially passedthrough the apparatus 10 including the sensoring system, both the redindicator light 42 and the yellow indicator light 42 will beilluminated. After the highly contaminated engine antifreeze coolantliquid has passed through the apparatus 10 a sufficient number of timessuch that the resistance or conductivity of same is respectively greaterthan or equal to 20,000 ohms, or less than or equal to 50 micromhos, thered indicator light 42 will disilluminate or go out, while the yellowindicator light 42 remains lit. The less contaminated engine antifreezecoolant may be continually circulated through the apparatus 10 until theyellow indicator light 42 disilluminates or goes out, indicating thatthe engine antifreeze coolant has been purified and/or cleansed ofundesirable ions, dissolved solids and particulates such that theresistance is greater than or equal to 20,000 ohms or the conductivityis less than or equal to 50 micromhos. It is readily apparent and withinthe spirit and scope of the present invention that the sensoring systemincluding the indicators 42--42 may be calibrated to illuminate ordisilluminated at any desired resistance or conductivity level for theengine antifreeze coolant liquid. In a more preferred embodiment of thepresent invention as will be more fully explained in greater detailbelow, the sensoring system includes only one indicator 42 (see FIGS. 8and 20) which will indicate, such as through illumination, when thepreviously suggested upstream ion exchange zone (which will be morefully identified below) has become exhausted. It is intended thatcontaminated engine antifreeze coolant liquid will be sufficientlypurified of contaminating ions with one pass through the apparatus 10 ofthis invention. Thus, after one pass, if the contaminated engineantifreeze coolant liquid has not been sufficiently expunged ofundesirable ions, the ion exchange zone is not effectively performingits function of removing contaminating ions from contaminated engineantifreeze coolant liquid and the one indicator 42 will illuminate toindicate such. When the one indicator 42 is illuminated, the operatorshould then investigate the ion exchange zone to determine if it hasbecome exhausted and is no longer capable of removing contaminating ionsfrom a contaminated engine antifreeze coolant liquid.

The slanting face 20F has protruding therefrom an inlet conduit cap 46and an outlet conduit cap 48 which respectively threadably engage aninlet conduit 50 and an outlet conduit 52 both of which pass through theslanted face 20F as best shown in FIG. 8. As also best shown in FIG. 8and further best shown in FIG. 19, inlet conduit 50 has engaged theretoconnection 53 which communicates with and is engaged to a conduit 58that extends to a connection 54 advantageously located in a line 56. Asshown in FIG. 19, line 56 extends from an engine block 60 to a heater 62which is for use in a vehicle to be heated. Engine antifreeze coolantliquid (i.e., water and a freezing point depressant, such as ethyleneglycol, etc.) is adapted to pass through cooling passages of an internalcombustion engine cooling system that may be conveniently defined by theheater 62 and line 56; a radiator 64 and lines or hoses 66 and 68 whichextend from the radiator 64 to the engine block 60; and a line 70connecting the heater 62 with the engine block 60. Not shown in FIG. 19is a coolant pump (i.e., a water pump) which may be conveniently locatedin line 66. During continued operation of the engine block 60, theengine antifreeze coolant liquid becomes contaminated with hydrocarbons(such as oil, grease, etc.), particulates [such as rust particles andprecipitates (calcium/iron salts, etc.)]; dissolved anions (e.g.chloride, sulfate, nitrate, carbonate, bicarbonate, silicate, fluoride,nitrate, sulfite, hydroxide, etc.); and dissolved cations [e.g. calcium,magnesium, sodium, potassium, iron, manganese, copper, aluminum, barium,arsenic, lead, cadmium, mercury, silver, chromium, zinc, and hydronium(acid), etc.]. In the past, contaminated engine antifreeze coolantliquid would be either drained or dumped into sewer lines, or collectedin drums and stored to be eventually collected by a hazardous wastecollector. One of the salient features of the present invention is thatsuch environmentally objectionable draining and storage is eliminated bycycling the contaminated engine antifreeze coolant liquid through theapparatus 10 of the present invention to remove undesirable particulatesand hydrocarbons as well as deleterious anions (including nitriteanions) and cations. More specifically for one preferred embodiment ofthe invention, contaminated engine antifreeze coolant liquid may beprovided by collecting it off the internal combustion engine coolingsystem from the line 58 at connection 53 and passed through theinternals of the apparatus 10 for purification through removal ofparticulates, hydrocarbons (such as oil, grease, etc.), ions (i.e.,anions and cations), and other contaminants. Purified and cleansedengine antifreeze coolant liquid is returned to radiator 64 through aline 72 that connects to outlet conduit 52 at connection 74. Connection74 is a juncture where the line 72 and outlet conduit 52 are joinedtogether such that the two communicate with each other. It is readilyapparent that initially purified and cleansed engine antifreeze coolantliquid may be and will be recycled through the apparatus 10 for furtherpurification and cleansing as long as the engine block 60 and/or a pump78 (see FIGS. 19 and 23) of the apparatus 10 continually run. Pump 78 isany type of suitable pump, such as centrifugal, which is capable oftaking a suction on a fluid for intaking the fluid, pumping the fluidand discharging the same at a desired location. In instances where theflow rate of the engine antifreeze coolant through the engine block 60is vastly different, such as much higher, than the flow rate capable ofbeing produced by the pump 78, it is recommended that the engine block60 be secured from running and only the pump 78 be employed for causingthe flow of engine antifreeze coolant liquid. More specifically furtherfor another preferred embodiment of the invention and as previouslyindicated, the contaminated engine antifreeze coolant liquid may becollected or provided from drums (or other suitable containers) where ithas been stored, passed through the internals of the apparatus 10 forpurification and discharged back into the drums after purification. Suchcollection of engine antifreeze coolant liquid from drums may beadvantageously obtained through a suction with pump 78 on the engineantifreeze coolant liquid situated in the drums. It is to be understoodthat the origin of the engine antifreeze coolant liquid to be providedand furnished to the apparatus 10 may be of any origin or genesis; andthe present invention is not to be limited by the origin or genesis ofthe engine antifreeze coolant liquid.

The apparatus 10 is provided with a valve 76 (e.g. a check valve) andthe pump 78, all disposed advantageously in inlet conduit 50 tocommunicate with the contaminated engine antifreeze coolant liquid.Valve 76 is a typical back pressure type check valve which is to preventflow-back of contaminated engine antifreeze coolant. Pump 78, as waspreviously mentioned, is for causing the flow of contaminated engineantifreeze coolant from a given source, and for pumping or transferringthe received contaminated engine antifreeze coolant liquid through theremaining internals of the apparatus 10, and through outlet conduit 52.For the embodiment of the invention in FIGS. 19 and 23, outlet conduit52 returns purified engine antifreeze coolant liquid into line 72 fordisposition back into the radiator 64. Further for the embodiment of theinvention in FIGS. 19 and 23, the contaminated engine antifreeze coolantliquid may be caused to be flowed from line 56, through the line 58 andinto the inlet conduit 50 by a running engine block 60 (and a coolantpump not shown in the drawings). As was previously mentioned, it is notnecessary for the engine block 60 to be running, as suction from thepump 78 alone is sufficient to cause the engine antifreeze coolantliquid to flow. Also disposed advantageously in inlet conduit 50 is thepressure gauge 34 extending therefrom to be exposed on and from theslanted face 20F. Inlet conduit 50 terminates in a filtering system,generally illustrated as 80, where precipitated particles as well asother particulates are to be removed along with any associatedhydrocarbons. The filtering system 80 may be any filtering systemcapable of functioning to remove and/or filter out hydrocarbons andparticles contained within the contaminated engine antifreeze coolantliquid. Preferably, for the embodiment of the invention in FIG. 19, thefiltering system 80 comprises a series of three (3) in line filters,identified as 82, 84 and 86 in FIGS. 19 and 23, that employ bothmechanical and active chemical (absorption) filtration. More preferably,there are two (2) mechanical filters and one (1) active chemical filter.The two (2) mechanical filters are preferably filters 82 and 86 and theactive chemical filter is filter 84. In a preferred embodiment of theinvention, each mechanical filter includes a filter container 88 havinga threaded neck 90 (see FIG. 18). Removably disposed in the filtercontainer 88 is a line or spun filter 92 such as the type purchasedunder the product numbers CU25WOT and SW05T of the Filter Cor Co. Eachline of the spun filter 92 may be manufactured from any suitablematerial, such as nylon or cotton, or the like. The spun filters 92--92are maintained in their respective filter container 88 by a top 94 thatthreadably engages the threaded neck 90 of the filter container 88. Eachtop 94 (as best shown in FIG. 18) is pierced by an inlet filter conduit96 and an outlet filter conduit 98, both communicating with the insideof each filter container 88 such that the engine coolant liquid (whichis to be filtered) can pass into the filter container 88 and out of sameafter being filtered by spun filter 92. Inlet filter conduit 96 is indirect communication with inlet conduit 50, and outlet filter conduit 98is communicatively engaged to an intermediate conduit identified as"108" below. Each spun filter 92 is produced to be capable of filteringout certain size particles and/or particulates, which may be of anypreferred size, depending on the desired results. Preferably, the spunfilter 92 in filter 82 possesses the capabilities of filtering outparticulates having a particle size of 25 microns or larger; andlikewise, the spun filter 92 in filter 86 can remove and/or filter outfrom the engine antifreeze coolant liquid particulates having a particlesize of 5 microns or larger. The 25 micron size spun filter 92 in filter82 initially removes the larger particles entrained in the engineantifreeze coolant liquid with the 5 micron size spun filter 92 infilter 86 subsequently removing the smaller particles entrained in theengine antifreeze coolant liquid along with the larger particles thatwere not filtered by and by-passed the 25 micron size spun filter 92 infilter 82. The active chemical (adsorption) filter 84 is straddled bythe two (2) mechanical filters 82 and 86 and functions to remove any ofthe hydrocarbons as well as other chemicals that are contained in theengine antifreeze coolant liquid. In a preferred embodiment of theinvention, the active chemical filter 84 comprises a filter container100 which holds activated carbon, such as in the form of particulatecharcoal 102 (see FIG. 17) In a more preferred embodiment of theinvention as best shown in FIG. 17, a filtering member 103, which ispreferably any mechanical filter means for filtering such as a straineror a screen or spun filter 92, is generally coaxially, concentricallydisposed in the filter container 100 with the particulate charcoal 102surrounding the filtering member 103. Preferably, the filtering member103 possesses the capabilities of removing and/or filtering out from theengine antifreeze coolant liquid particulates having a particle size of5 microns or larger. The activated carbon particulate of this inventionis an amorphous form of carbon characterized by high adsorptivity formany hydrocarbons, chemicals, and colloidal solids. The carbon isobtained by the destructive distillation of carbonaceous materials (suchas animal bones, nut shells and wood); and is "activated" by heating ata temperature of 800°-900° C. with steam and/or carbon dioxide,resulting in an internal structure defined with porosity (i.e.,honeycomb-like). The internal surface area of the activated carbon ofthis invention may be of any particulate size, such as from about 70 m²/g to about 2000 m² /g and with a specific gravity of from about 0.08 toabout 0.5. Preferably the activated carbon is 12×40 mesh with a surfacearea of about 600 m² /g and a specific gravity of 0.1 to 0.4. Aspreviously indicated, the filter container 100 preferably has thefiltering member 103 and the particulate charcoal 102 surrounding thefiltering member 103, as illustrated in FIG. 17. The filter container100 for the activated carbon also has a threaded neck (not shown in thedrawings) similar to neck 90 of filter container 88 for threadablyengaged with a top 104. As further best shown in FIG. 17, top 104 has apair of opposed openings, with one of the opposed openings receiving theoutlet filter conduit 98 from filter 82 to emit engine antifreezecoolant liquid that has been filtered by filter 82, and with the otheropposed opening receiving the inlet filter conduit 96 of the filter 86to exit engine antifreeze coolant liquid that has been filtered by theactivated carbon in the chemical filter 84.

In the preferred embodiment of the invention in FIG. 23, filter 82 ispositioned in front of pump 78 in order to initially remove or filterout the particulates having a certain particle size, preferably 25microns or larger. Such disposition of filter 82 provides for removal oflarger particulates from the engine antifreeze coolant liquid beforepassing through pump 78. Particulates of the preferred 25 microns insize or larger could clog or plug the pump 78, especially if theparticulates agglomerate. Thus, in this embodiment of the invention, thefiltering system 80 is split or severed, with filter 82 being disposedin front of pump 78 and gauge 34, and with filters 84 and 86 beingpositioned downstream from pump 78 and gauge 34. Inflowing contaminatedengine antifreeze coolant liquid flows into filter 82 where at leastpart of the particulates of the preferred 25 micron size or larger isremoved through initial filtration. From filter 82, the initiallyfiltered engine antifreeze coolant liquid passes to pump 78 for pumpingand transferring into the filter 84 where hydrocarbons and otherchemicals can be filtered or otherwise removed from the engineantifreeze coolant liquid. From filter 84 the engine antifreeze coolantliquid passes into filter 86 where particulates of a smaller size, saypreferably 5 microns or larger, can be removed from the engineantifreeze coolant liquid. After the smaller size particulates have beenremoved, the engine antifreeze coolant liquid passes into anintermediate conduit (identified below as "108"). Further with respectto the preferred embodiment of the invention in FIG. 23, a heatexchanger 105 (or any cooler member) is disposed between connection 53and valve 76 to cool incoming engine antifreeze coolant to a lowertemperature, preferably to 120° F. or lower, to prevent damage to any ofthe internal components of the apparatus 10, especially those that maybe sensitive to heat. Heat exchanger 105 may be any type of heatexchanger or cooler, preferably of the type having the cooling mediumbeing self-contained.

The mechanical filters 82 and 86 having spun filters 92--92 removesuspended solids and/or gross contaminants from engine antifreezecoolant liquid while the chemical filter 84 (or activatedcarbon/charcoal 102, or the activated particulate charcoal 102 incombination with the filtering member 103) assist in removing entrainedhydrocarbons (e.g. solvents, oils, surfactants, and degradationproducts, such as organic acids). The functionality of the activatedcarbon is very important because as ethylene glycol oxidizes in service,various low molecular weight organic acids are produced. Furthermore,chemicals employed to flush radiators often contain solvents,surfactants, and acids, such as citric acid. All of these deleteriouschemicals, hydrocarbons and substances can be absorbed when using thecorrect activated carbon (or the correct activated carbon in combinationwith filtering member 103) in filter 84 and utilizing the proper flowrate through the filter 84. In a more preferred embodiment of thepresent invention the activated carbon to be employed is granular inform, 12×40 mesh, with an internal surface area of 600 m² /g, and soldunder the trademark DARCO, a trademark of the American Norit Co. Thepreferred flow rate for pump 78 to pump engine coolant liquid throughthe internals of the apparatus 10 including the filtering system 80 isfrom about 1 to about 10 gallons per minute. While the preferredmechanical filters 82 and 86 are of the spun filter type with respectivesizes being 25 microns and 5 microns, it should be understood that thespirit and scope of the present invention encompasses any type ofmechanical filters possessing any suitable size, provided that anyundesirable suspended particles can be removed. Similarly, while thepreferred chemical filter 84 is of the active chemical (adsorption)type, more specifically activated carbon or charcoal, it should beunderstood that the spirit and scope of the present invention alsoencompasses any type of chemical filter that is capable of removingdeleterious hydrocarbons and chemicals, such as, by way of example only,the particulate charcoal 102 in combination with the filtering member103.

The apparatus 10 additionally comprises an intermediate conduit 108extending from the filtering system 80, more specifically from filter86, to an ion exchange zone, generally illustrated as 110, whereindeleterious ions (i.e., anions and cations) contained within the engineantifreeze coolant liquid are removed. The ion exchange zone 110 is oneof the salient features of the present invention and has a number ofpreferred embodiments, each of which will be explained in detail below.After deleterious ions have been removed from the engine antifreezecoolant liquid in the ion exchange zone 110, the engine coolant liquidleaves the ion exchange zone 110 and passes into the outlet conduit 52,as best shown in FIG. 19. As further best shown in FIG. 19 and moreparticularly in FIG. 15, the outlet conduit 52 between connection 74 andthe ion exchange zone 110 has a sensoring zone, generally illustrated as112, and an electronic valve 114 disposed advantageously therein suchthat the engine antifreeze coolant liquid may pass therethrough beforebeing discharged from conduit 52, such as for flowing through line 72and back into the radiator 64. In a preferred embodiment of the presentinvention, the sensoring zone 112 includes the indicator 42, andmeasures and indicates the conductivity of the engine antifreeze coolantliquid, as a measure of the degree of purification of the engineantifreeze coolant liquid.

When the engine antifreeze coolant liquid leaves the ion exchange zone110 and passes into the sensoring zone 112 via outlet conduit 52, thesensoring zone 112 continually monitors the resistivity and/orconductivity of the engine antifreeze coolant liquid as a measure of theeffectiveness of the ion exchange zone 110 in removing ions. Should theion exchange zone 110 become defective and cease to remove contaminatingions from the contaminated engine antifreeze coolant liquid, theresistivity of the engine antifreeze coolant liquid after it passesthrough the ion exchange zone 110 will decrease below a predetermined,preferred value (e.g. 20,000 ohms) and the indicator 42 alerts theoperator (such as becoming lit if indicator 42 is a light) that asufficient quantity of deleterious ions has not been removed by the ionexchange zone 110. Stated alternatively, if the ion exchange zone 110becomes exhausted and can no longer effectively remove deleterious ionsfrom a contaminated engine antifreeze coolant liquid, the conductivityof the engine antifreeze coolant liquid leaving the ion exchange zone110 will increase to a predetermined, preferred value (e.g. 50micromhos) and the indicator 42 will signal that the engine antifreezecoolant liquid is not being purified of contaminating ions by the ionexchange zone 110 to a desired degree of purification. In suchsituations the ion exchange zone 110 typically has to be replenishedwith effective ion exchanger(s). Furthermore, with respect to apreferred embodiment of the present invention, the sensoring zone 112additionally comprises at least one T-fitting 116 (see FIG. 10)advantageously positioned in outlet conduit 52 before valve 114 andafter the ion exchange zone 110. T-fitting 116 has a neck 118wherethrough a probe, generally illustrated as 120, removably passes andlodges. The probe 120 is formed with a pair of prongs 121 and 122 whichcontacts the engine antifreeze coolant liquid as it passes through theT-fitting 116. Prong 121 has conveniently been labeled as the positive(+) terminal with conductor 123 extending therefrom. Similarly, prong122 has conveniently been labeled as the negative (-) terminal withconductor 125 extending therefrom. The indicator 42 (i.e., theresistance instrument) and the probe 120 (i.e., the electrode cell) areformed and calibrated such that the conductivity or resistance of theindicator 42 (more specifically, the indicator light 42) is matched withthe conductivity or resistance of the probe 120. Direct current iscontinually being sent to the negative terminal prong 122 from a powersource. If the engine antifreeze coolant liquid possesses apredetermined resistance and conductivity after passing through the ionexchange zone 110, direct current will pass from the negative terminalprong 122, through the engine antifreeze coolant liquid, and through thepositive terminal prong 121, closing a circuit (including the indicator42) with a power source. When the circuit is closed, the indicator 42 isenergized to alert the operator that the ion exchange zone 110 is notremoving the contaminating ions and the engine antifreeze coolant liquidis still contaminated. If the ion exchange zone 110 is operatingeffectively, the engine antifreeze coolant liquid leaving the ionexchange zone 110 possesses a degree of purification and a high enoughresistivity (or a low enough conductivity) that direct current can notflow through the engine antifreeze coolant liquid from the negativeterminal prong 122 and the indicator 42 will not be energized andremains dormant. As long as the indicator 42 is not energized and notactivated, the engine antifreeze coolant liquid leaving the ion exchangezone 110 possesses a desired degree of purification and a resistivity(or a conductivity) that direct current does not pass from the negativeterminal prong 122, through the engine antifreeze coolant liquid, andthrough the positive terminal prong 121. The probe 120 including theprongs 121-122 and the respective disposition (i.e., spacing) of sameare calibrated such that with a given, predetermined current and voltageacross the prongs 121-122 and a certain resistivity (or conductivity) inthe engine antifreeze coolant liquid, direct current will flow from thenegative terminal prong 122, through the engine antifreeze coolantliquid, and through the positive terminal prong 121. Preferably, theprobe 120 (including the prongs 121-122) is calibrated such that at 12volts across the prongs 121-122 the indicator 42 as a light willilluminate if the resistivity of the engine antifreeze coolant liquidfalls and decreases to (or below) 20,000 ohms or the conductivityincreases to (or above) 50 micromhos. As the parts per million (ppm), orgrains per gallon (gpg), of ionic particles in the engine antifreezecoolant liquid increases such that the engine antifreeze coolant liquiddoes not possess a desired degree of ion purification, the resistivityof the engine antifreeze coolant liquid between the prongs 121-122 hasdecreased and the conductivity has increased. Thus, the sensoring zone112 of the present invention continually monitors the resistivity (orconductivity) of the engine antifreeze coolant liquid leaving the ionexchange zone 110, as a measure of the degree of purification of theengine antifreeze coolant liquid and as a measure of the effectivenessof the ion exchange zone 110 in removing contaminating ions. If the ionexchange zone 110 becomes ineffective, the ion exchanger(s) (which willbe identified hereinafter) in the ion exchange zone 110 should bereplaced and/or otherwise replenished.

The ion exchange zone 110 is a typical ion exchange which may be definedas a reversible chemical reaction between a solid (ion exchanger) and afluid (usually a water solution) by means of which ions may beinterchanged from one substance to another. The superficial physicalstructure of the solid, or the ion exchanger, is not affected.Typically, a fluid, such as engine antifreeze coolant liquid, is passedthrough a bed of the solid/ion exchanger which is in the form of ionexchange synthetic resins with active groups. Ions on the resin areexchanged with ions in the liquid. In the present invention,predetermined ions on the resins are exchanged with the ions (i.e.,cations and anions) in the engine antifreeze coolant liquid.

The ion exchange zone 110 has a number of preferred embodiments. In thepreferred embodiment of the invention in FIG. 21, the ion exchange zone110 comprises a pair of mixed bed ion exchangers 124 and 126, eachhaving a mixture of anion and cation exchange resins. The two ionexchangers 124 and 126 are interconnected by conduit 128. A zone forseparating or a separator, generally illustrated as 134, is engagedcommunicatively with the mixed bed ion exchanger 126 via conduit 136 inorder to receive the engine antifreeze coolant liquid after it leavesmixed bed ion exchanger 126 to remove nitrogen containing compounds(such as gas containing nitrogen and selected from the group consistingof nitric oxide, nitrogen dioxide, and mixtures thereof) that may haveformed in mixed bed ion exchangers 124 and/or 126. How nitrogencontaining compounds (such as nitrogen containing gas) form in ionexchangers, and in particular cation-ion exchangers, will be explainedin greater detail below.

In a more preferred embodiment of the present invention, the ionexchange zone 110 comprises a cation exchange bed ion exchanger 130, andan anion exchange bed ion exchanger 132 in communication with the cationexchange bed ion exchanger 130 by the conduit 128, as best depicted inFIG. 19. In another more preferred embodiment of the present invention,as best shown in FIG. 22, the ion exchange zone 110 comprises the cationexchange bed ion exchanger 130 and the anion exchange bed ion exchanger132 in communication with the cation exchange bed ion exchanger 130 viathe conduit 128, and the separating zone 134 wherein compoundscontaining nitrogen [i.e., NO.sub.(g) (nitric oxide) and/or NO₂(g)(nitrogen dioxide)] are removed from the engine antifreeze coolantliquid after it leaves the anion exchange bed ion exchanger 132 throughthe conduit 136 that intercommunicates the separating zone 134 with theanion exchange bed ion exchanger 132. The nitrogen-containing compounds,such as nitrogen containing gas selected from nitric oxide and/ornitrogen dioxide, initially form in the cation exchange bed ionexchanger 130 and perhaps continue to form through a series ofdecomposition and reactions in the anion exchange bed ion exchanger 132as more particularly explained below. One of the salient features of thepresent invention is the removal of nitrogen-containing compounds(especially deleterious nitrogen-containing gas) from the engineantifreeze coolant liquid after it leaves the anion exchange bed ionexchanger 132.

After the engine antifreeze coolant liquid leaves the ion exchange zone110, more specifically the separating zone/separator 134, it passes viaconduit 52 through the sensoring zone 112 wherein the degree ofpurification of the engine antifreeze coolant liquid is being monitoredin accordance with the procedure previously described. From thesensoring zone 112 the engine antifreeze coolant liquid passes viaoutlet conduit 52 through the valve 114 and continues through outletconduit 52 for eventual discharge through connection 74 into anotherline, such as line 72. After the engine antifreeze coolant liquid hasbeen purified to a desired level, the engine antifreeze coolant liquidtypically comprises an aqueous coolant (i.e., water) and ethylene glycol(if a freezing point depressant was initially employed). Essentially alloils/greases (i.e., hydrocarbons), particulates (e.g. rust particles),cations and anions have been removed, including any and all inhibitorsand other additives that were previously contained in the engineantifreeze coolant liquid before passing through the apparatus 10 forpurification. These inhibitors and additives, which are to be added backinto purified engine antifreeze coolant liquid before it is employed forfurther use, may include any types of inhibitors and additives including(depending on the use of the engine antifreeze coolant liquid)conventional scale inhibitors (e.g. tetrasodium pyrophosphate andpolyacrylates having a molecular weight less than 5000), corrosioninhibitors, microbrocides (e.g. halogens, quarternary amines, methylenebis thiocyanate, tributyltin oxide, etc.), antifoaming agents, dyes,and/or iron dispersants, etc. The addition of inhibitors and otheradditives may be performed at any suitable location such as outsideapparatus 10 or merely modifying outlet conduit 52 such that theinhibitors/additives may flow into outlet conduit 52 as the purifiedengine antifreeze coolant liquid is flowing therethrough to leave theapparatus 10. In a preferred embodiment of the present invention, theorigin of the engine antifreeze coolant liquid is from the coolingsystem of an automobile, truck, tractor or any other vehicle; and thus,will always include corrosion inhibitors for various dissimilar metalsfrom which the cooling system (including the engine) is manufactured,such as copper, brass, aluminum, solder, steel, and cast iron.

In the electrical schematic in FIG. 20 for a 110 volt power source asopposed to a 12 volt source (i.e., the battery of a car), the apparatus10 includes a pair of inhibitor additive pumps 202 and 204 whichrespectively have conductors 206 and 208 leading to a conductor 210 thatin turn leads to a 110 volt to 12 volt converter 214. Conductors 206 and208 respectively have additive pump switches 216 and 218 for energizingthe pumps 202 and 204. Pumps 202 and 204 also have conductors 220 and222 leading respectively therefrom to a conductor 224 that electricallyengages the 110 volt to 12 volt converter 214. Conductors 210 and 224are electrically engaged to the sensoring zone 112; more specifically,to the conductors 123 and 125 which electrically interconnectrespectively conductor 210 with conductor 224. As illustrated in FIG.20, indicator light 42 is electrically in series in conductor 125 whichelectrically engages probe 120 along with conductor 123. Leading fromthe converter 214 to a terminal strip, generally illustrated as 230, areconductors 232 and 234. A ground conductor 236 leads from the terminalstrip 230 to a ground 238. Also leading from the converter 214 to a plugor receptacle 240 (which may be conveniently mounted on the cabinet 12of the apparatus 10) are conductors 242, 244 and 246. Conductor 242conveniently has a 30 amp fuse 248. A cord (not shown in the drawings)extends from the receptacle or plug 240 to a 110 volt power source. Thecord is preferably equipped with a Ground Fault Interrupter (not shownin the drawings) to provide protection to the operator. Extending fromthe terminal strip 230 to the on/off switch 32 (i.e., the power switch)is conductor 250. The on/off switch 32 is electrically engaged to valve114 and pump 78 by conductor 252 and 254 respectively. A pressure reliefswitch 260 is respectively electrically engaged to on/off switch 32 andto valve 114 by conductors 262 and 264. Pump 78 is electricallyconnected to the terminal strip 230 by conductors 270 and 272. Inoperation, power (e.g. 110 volt power) is supplied to the plug 240 bythe cord (not shown in the drawings), and is distributed to the terminalstrip 230 via conductors 242, 244 and 246. The terminal strip 230 isprotected by the 30 amp overload fuse 248 and is grounded to ground 238by conductor 236. When the on/off switch 32 is turned on, power isprovided to valve 114 and pump 78. When valve 114 receives power, it isopened and engine antifreeze coolant liquid is permitted to flow throughinlet conduit 50, through the filtering system 80, through intermediateconduit 108 and the ion exchange zone 110, and through the separatingzone 134 and into the outlet conduit 52 for passage through thesensoring zone 112 and the valve 114 itself. When pump 78 receives thepower, the engine antifreeze coolant liquid is caused to flow as suchand is further caused to be pumped from the cooling system of a vehicleor from any other source, such as drums (not shown in the drawings).Turning the on/off switch 32 to "off" closes the valve 114 anddeenergizes the pump 78, all of which stops and prevents the flow ofengine antifreeze coolant liquid. Turning the pressure relief switch 260to an "on" position without turning on the on/off switch 32 opens thevalve 114 without activating the pump 78; thus allowing the operator torelieve pressure within the internals of the apparatus 10 for anydesired purpose, such as for changing the deionization container (e.g. acation exchange bed ion exchanger and/or an anion exchange bed ionexchanger, all of which will be identified hereinafter). When thepressure relief switch 260 and the on/off switch 32 are turned "off",the valve 114 closes. The terminal switch 230 transmits the power to theconverter 214 which converts 110 volts to 12 volts. The converter 214,when turned on, supplies 12 volt power and direct current to theinhibitor additive pumps 202 and 204 when the additive pump switches 216and 218 are pushed to the "on" position. The switches 216 and 218 arepreferably spring loaded to return to the "off" position. The converter214 also supplies 12 volt power and direct current to the probe 120 andthe indicator light 42.

The corrosion inhibitors for the present invention preferably includefilm forming polar organic materials such as MBT(mercaptobenzothiazole); divalent cations such as Zn⁺² ; anions such asmolybdate and phosphate; and certain sodium and/or potassium salts. Morepreferable, the corrosion inhibitor(s) of the present invention isselected from the group consisting of sodium tetraborate (Na₂ B₄ O₇.5H₂O); sodium metasilicate (Na₂ SiO₃.5H₂ O); sodium nitrate (NaNO₃); sodiumnitrite (NaNO₂); sodium mercaptobenzothiazole (NaMBT); sodiumtolyltriazole (C₇ H₆ N₃ Na); disodium monohydrogen phosphate (Na₂HPO₄.7H₂ O); sodium molybdate (Na₂ MoO₄.2H₂ O); and mixtures thereof.

In a preferred embodiment, the corrosion inhibitors and additives of thepresent invention to be admixed with the engine antifreeze coolantliquid are formulated into a pair of additive mixtures (or additivepackages) for automotive purposes; and a pair of additive mixtures (oradditive packages) for heavy duty motor purposes. The automotiveinhibitor and additives packages comprises preferably a first mixture(which may be identified as 5502A) preferably comprising a major amountof an aqueous phosphate solution; and a minor amount of an antifoamagent, preferably polyoxypropylene-polyoxyethylene block copolymer,available commercially under the product name of Pluronic L61 from BASFCorp.; and a dye, preferably CI Acid Blue 9, Disodium salt (C₃₇ H₃₄ N₂S₃ Na₂) available commercially under the product name of CobratecColorant 0950; and a second mixture (which may be identified as 5502B)preferably comprising a major amount of various inorganic and organiccorrosion and scale inhibitors in an aqueous medium; and a minor amountof an antifoam agent, preferably polyoxypropylene-polyoxyethylene blockcopolymer, available commercially under the product name of Pluronic L61from BASF Corp.; and a dye, preferably Dipotassium Fluorescein, AcidYellow 73 (C₂₀ H₁₀ O₅ K₂) available commercially under the product nameCobratec Colorant 7335. The 5502A mixture and the 5502B mixture of theautomotive package are preferably combined in a ratio of from about1:0.5 to about 1:1.5 by wt., more preferably in a ratio of 1 to 1 by wt.The combined 5502A mixture and 5502B mixture are to be added to thepurified engine antifreeze coolant liquid such that the new,"rejuvenated" engine antifreeze coolant liquid comprises a sufficientquantity of the combined 5502A and 5502B mixture. The two dyes may be ofany suitable color, preferably diverse in color such that when combinedby the automotive package being added to the purified engine antifreezecoolant liquid which is basically clear and colorless, the new,"rejuvenated" engine antifreeze coolant liquid has a known coloration toprovide a means for ensuring that both the 5502A mixture and the 5502Bmixture are indeed present and that the purified engine antifreezecoolant liquid has been properly treated with the required inhibitorsand additives to fully protect cooling system (including the engine) ofthe automotive vehicle that is to receive the new, "rejuvenated" engineantifreeze coolant liquid. In a preferred embodiment of the invention,the dye for the 5502A mixture is blue in color so that the 5502A mixtureis also blue in color, and the dye for the 5502B mixture is yellow incolor to give the 5502B mixture a yellow color. When the blue 5502Amixture is mixed with the yellow 5502B mixture, the completed engineantifreeze coolant liquid has a blue/green coloration, ensuring thatboth additive mixtures are present.

The heavy duty inhibitor and additive package (particularly useful fordiesel machinery such as trucks and the like) comprises preferably afirst mixture (identified as 5702A) comprising a major amount of anaqueous phosphate solution; and a minor amount of an antifoam agent,preferably polyoxypropylenepolyoxyethylene block copolymer, availablecommercially under the product name of Pluronic L61 from BASF Corp.; anda dye, preferably CI Acid Blue Disodium salt (C₃₇ H₃₄ N₂ S₃ Na₂)available commercially under the product name of Cobratec Colorant 0950;and a second mixture which may be identified as 5702B preferablycomprising a major amount of various inorganic and organic corrosion andscale inhibitors in an aqueous medium; and a minor amount of an antifoamagent, preferably polyoxypropylenepolyoxyethylene block copolymer,available commercially under the product name of Pluronic L61 from BASFCorp., and a dye, preferably Dipotassium Fluorescein, Acid Yellow 73(C₂₀ H₁₀ O₅ K₂) available commercially under the product name CobratecColorant 7335. The 5702A mixture and the 5702B mixture of the heavy dutypackage are preferably combined in a ratio of from about 1:0.5 to about1:1.5 by wt., more preferably in a ratio of 1 to 1 by wt. The combinedor admixed 5702A mixture and 5702B mixture for the heavy duty packageare to be added to the purified engine antifreeze coolant liquid suchthat the new, "rejuvenated" engine antifreeze coolant liquid for heavyduty machinery comprises a sufficient quantity of the combined 5702A and5702B mixture for the heavy duty inhibitor/additive package. Similar forthe two dyes of the automotive inhibitor/additive package, the two dyesin the heavy duty inhibitor/additive package may be of any suitablecolor, preferably diverse in coloration such that when combined by theheavy duty package being added to the purified engine antifreeze coolantliquid, the new, "rejuvenated" engine antifreeze coolant liquid forheavy duty use has a known coloration, providing a failsafe means forensuring that the new, "rejuvenated" engine antifreeze coolant liquidfor heavy duty use has been properly treated with the appropriateinhibitors and additive to protect the cooling system and the engine ofthe heavy duty vehicle that is to receive the new, "rejuvenated" heavyduty engine antifreeze coolant liquid. In a preferred embodiment of theinvention, the two dyes employed in the heavy duty package are ofidentical, diverse color as the two dyes employed in the automotivepackage. More specifically, the dye for the 5702A mixture has a bluecolor and the dye for the 5702B mixture has a yellow color such that thecompleted engine antifreeze coolant liquid for heavy duty use has ablue/green coloration, again ensuring that both additive mixtures arepresent. Thus, another one of the salient features of the presentinvention is the providing of a first inhibitor/additive mixture of afirst known color; the providing of a second inhibitor/additive mixtureof a second known color different in color from the first known color;and adding the first inhibitor/additive mixture and the secondinhibitor/additive mixture to a purified engine antifreeze coolantliquid such that the admixture of the engine antifreeze coolantliquid/first mixture/second mixture obtains and/or results in a knowncolor. The resulting known color of the admixture is indicative of thefact that the engine antifreeze coolant liquid has been properly treatedto protect the cooling system of an engine from corrosion, and etc. Moreparticularly, the resulting known color ensures that the necessaryinhibitors/additives are present to re-inhibit the purified engineantifreeze coolant liquid (i.e., purified ethylene glycol/water mixture)to an ASTM D3306 quality level.

Recapitulating, a first mixture (e.g. 5502A or 5702A) would typicallycontain a phosphate/silicate/nitrate based inhibitor and a dye of knowncolor (such as blue), which dye would be of such a strength to functionto make the entire first mixture the same color of the dye when thephosphate/silicate/nitrate based inhibitor, and the antifoam agent, andthe dye are mixed together. Similarly, the second mixture (e.g. 5502B or5702B) would also typically contain a phosphate/silicate/nitrate basedinhibitor and an antifoam agent and a dye of a known color (such asyellow), which dye would also function to make the entire second mixturethe same color of the dye when the phosphate/silicate/nitrate basedinhibitor, the antifoam agent and the dye are mixed together. With thecolor of the first mixture known and the color of the second mixtureknown, when the first and second mixtures are mixed together and addedto the purified engine antifreeze coolant liquid (i.e., ethylene glycoland water, which is clear and/or the color of water), the resultingengine antifreeze coolant liquid will have a predictable known color.Thus, the resulting engine antifreeze coolant liquid with a predictableknown color would indicate that the first and second mixtures wereindeed added to the purified engine antifreeze coolant liquid.

The resins (i.e., ion exchange materials) for the mixed bed ionexchangers 124 and 126, the cation exchange bed ion exchanger 130, andthe anion exchange bed ion exchanger 132 are granular and poroussynthetic resins typically manufactured from polymeric material such asstyrene divinylbenzene, crosslinked styrene/divinylbenzene, andcrosslinked acrylic copolymers such as acrylic divinylbenzene matrix, orany other material which is capable of containing active groups (e.g.sulfonic, carboxylic, phenolic, or substituted amino groups) that givethe resin the property of combining with or exchanging ions between theresin and a solution such as contaminated engine antifreeze coolantliquid. Preferably, the synthetic resins of this invention aremanufactured from a polymer, such as the styrene divinylbenzenecopolymer, that serves as a backbone support for acidic or basicfunctional groups. The acidic functional groups exchange cations(positively charged ions) and may be either strong or weak in acidstrength. The basic functional groups exchange anions (negativelycharged ions) and may be either strong or weak in base strength.

Typical weak acid cations exchange resins are of the carboxylic acidtype (--COOH) cation exchangers. Examples of such carboxylic acid typecation exchangers include carboxylic divinyl benzene copolymers,copolymers of maleic anhydride with styrene and divinyl benzene.Suitable weak acid cation exchange resins include CCR-2 available fromDow Chemical Company, IR 84 available from Rohm & Haas, and IONAC® CCand IONAC® CNN available from Sybron Chemicals Inc. A typical structuraldiagram for a weakly acidic cation exchanger structure (acrylic divinylbenzene mixture) would be: ##STR1## A weak acid cation exchange reactioncan be represented as P--COOH+M⁺ →P--COO⁻ M⁺ +H⁺ with P symbolizing thepolymer support and M⁺ generally representing a positively charged ion.Weak acid cation exchange resins exhibit a high affinity for hydrogenions; that is, the resins hold on more tightly to their hydrogen ion,especially when compared to strong acid cation exchange resins.

Typical strong acid cation exchange resins include hydrogen and sodiumzeolites and hydrogen and sodium sulfonate resins. Examples of suchstrong acid cation exchange materials include HCR-S or HGR-W availablefrom Dow Chemical Company, IK 120+ available from Rohm & Haas ChemicalCompany, and IONAC® C-249 available from Sybron Chemicals Inc. A typicalstructural diagram for a strong cation exchanger structure(styrene-divinylbenzene matrix) having a sulfonic acid (--SO₃ H)functional group is: ##STR2## A strong acid cation exchange reaction canbe represented as: P--SO₃ H+M⁺ →P--SO₃ M⁺ +H⁺ with P symbolizing thepolymer support and M+ generally representing a positively charged ion.The strong acid cation exchanger is more willing to donate a hydrogenion (H⁺) than the weak acid cation exchange resin; and thus, is moreeffective at removing cations from the engine antifreeze coolant liquidthan a weak acid cation exchange resin. As a hydrogen ion is readilyreleased into the effluent/engine antifreeze coolant liquid, a counterion (a cation) is removed and retained from the effluent/engineantifreeze coolant liquid by the functional group (e.g. sulfonate group)of the strong acid cation exchange resin to maintain electricalneutrality.

Typical weak base anion exchange resins are of the aminated basic type(--NHR₂ ⁺) anion exchangers. Examples of such aminated basic type anionexchanges include styrene divinylbenzene matrix and epoxy-amine matrix.Suitable weak basic anion exchange resins include IONAC® AFP-329available from Sybron Chemicals. A typical structural diagram for aweakly basic anion exchanger structure (styrene-divinyl-benzene matrix)would be: ##STR3## A weak base anion exchange reaction can berepresented by: ##STR4## with P symbolizing the polymer support, Rrepresenting a radical such as --CH₃, and X⁻ generically representing anegatively charged ion. Weak basic anion exchange resins exhibit a highaffinity for hydroxide ions; that is, the resins hold on more tightly totheir hydroxide ion, especially vis-a-vis to a strong basic anionexchange resins. Typical strong basic anion exchange resins includestyrene divinylbenzene. Examples of such anion exchange materials areASB-1 from Sybron Chemicals, SBR and SAR available from Dow ChemicalCompany and IKA 400 available from Rohm & Haas Chemical Company. Atypical structural diagram for a strong base Type 1 anion exchangerstructure (styrene-divinylbenzene matrix) would be: ##STR5## For a Type2 anion exchanger structure, a hydroxide ion would replace the chlorideion in the Type 2 anion exchanger structure. A strong base anionexchange reaction can be represented as:

    P--NR.sub.3.sup.+ OH.sup.- +X.sup.- →P--NR.sub.3.sup.+ X.sup.- +OH.sup.-

with P symbolizing the polymer support, R representing a radical such as--CH₃, and X⁻ generically representing a negatively charged ion.

The strong base anion exchange resin is more willing to donate ahydroxide ion (OH⁻) than the weak base anion exchange resin. Morespecifically, a strongly basic group, such as a quaternary ammoniumhydroxide (--NR₃ OH), on an anion exchange resin readily donates itsassociated hydroxide ion to the engine antifreeze coolant liquid,provided an anion is available in the engine antifreeze coolant liquidto associate with the resulting quaternary ammonium group (--NR₃ ⁺) tomaintain electrical neutrality. In contrast, a weakly basic functionalgroup, such as --NHR₂ or a tertiary amine, on an anion exchange resinexerts a much smaller force of attraction towards anions in the engineantifreeze coolant liquid. Additionally, at a high pH (i.e., above about8.0) weakly basic functional groups are converted into a non-ionic formwhich affectively deactivates the ion-exchange properties of the anionexchange resin.

In a preferred embodiment of the present invention depicted in FIG. 21,the mixed bed ion exchanger 124 comprises a plurality of strong acidcation exchange resins in the Na+ form and a plurality of strong baseanion exchange resins in the Cl- form, all comingled together randomlyand contained in a container. Similarly, the mixed bed ion exchanger 126is a plurality of strong acid cation exchange resins in the H+form and aplurality of strong base anion exchange resins in the OH- form, allcomingled together randomly and contained in a container. The preferredstrong acid cation exchange resin in the Na+form is a bead-form resinthat is commercially available as IONAC® C-249 from Sybron ChemicalsInc. IONAC® C-249 has a crosslinked styrene/divinylbenzene polymerstructure with a --SO₃ --Na⁺ functional structure. The preferred strongacid cation exchange resins in the H⁺ form is a bead-form resin that iscommercially available as IONAC® C-249 from Sybron Chemicals Inc. IONACC-249 has a styrene divinylbenzene polymer structure with a --SO₃ --H⁺functional group. The strong base anion exchange resins in the Cl⁻ formis preferably a bead-form resin that is commercially available as IONAC®ASB-2HP Type 1 from the Sybron Chemicals Inc. IONAC® ASB-2HP has a Type1 styrene-divinylbenzene polymer structure with --CH₂ N(CH₃)₃ Clfunctional groups. The strong base anion exchange resin in the OH- formis preferably a bead-form resin that is commercially available as IONAC®ASB-2HP Type II from Sybron Chemicals Inc. IONAC® ASB-2HP has a Type IIstyrene-divinylbenzene polymer structure with a --CH₂ N(CH₃)₃ OHfunctional group.

In the preferred embodiment of the present invention depicted in FIG.21, contaminated engine antifreeze coolant liquid flows through conduit108, preferably at a flow rate of from about 1 gal. per min. to about 10gal. per min., and into the mixed bed ion exchanger 124 where the strongacid cation exchange resins in the Na+ form removes at least some of thecations (e.g. calcium, magnesium, sodium, potassium, iron, manganese,copper, aluminum, mercury, varium, arsenic, lead, cadmium, silver,chromium, zinc, and hydronium, etc.) from the contaminated engineantifreeze coolant liquid while essentially simultaneously releasingthereinto their associated sodium ion (Na+). Concomitantly, the strongbase anion exchange resins in the Cl⁻ form in the same mixed bed ionexchanger 124 removes at least some of the anions (e.g. chloride,sulfate, nitrate, carbonate, bicarbonate, silicate, fluoride, nitrite,sulfite, hydroxide, etc.) from the contaminated engine antifreezecoolant liquid while essentially simultaneously releasing thereintotheir associated chloride ion (Cl⁻). After a residence of from about 5mins. to about 15 mins. in the mixed bed ion exchanger 124, the engineantifreeze coolant liquid (containing released sodium and chloride ions,and perhaps some residual anions and cations which were not removed)leaves the mixed bed ion exchanger 124 through conduit 128 and passesinto the mixed bed ion exchanger 126, preferably at the same flow rateof from about 1 gal. per min. to about 10 gal. per min. In the mixed bedion exchanger 126, the strong acid cation exchange resins in the H⁺ formremoves at least some of the released sodium ions (i.e., previouslyreleased from the strong acid cation exchange resins in the Na+ formsituated in mixed bed ion exchanger 124) in the engine antifreezecoolant liquid while essentially simultaneously releasing thereintotheir associated hydrogen ion (H⁺). Concominantly, the strong base anionexchange resins in the OH⁻ form in the same mixed bed ion exchanger 126removes at least some of the released chloride ions (i.e., previouslyreleased from the strong base anion exchange resins in the Cl⁻ formsituated in mixed bed ion exchanger 124) in the engine antifreezecoolant liquid while essentially simultaneously releasing thereintotheir associated hydrogen ion (OH-). The released hydrogen ions and thereleased hydroxide ions can combine to form water (H₂ O) which becomespart of the water/aqueous phase of the engine antifreeze coolant liquid.After a residence time of from about 5 mins. to about 15 mins. in themixed bed ion exchanger 126, the engine antifreeze coolant liquid exitsmixed bed ion exchanger 126 and passes into conduit 136, which aspreviously indicated, intercommunicates the separating zone 134 with themixed bed in ion exchanger 126.

When the engine antifreeze coolant liquid passes into conduit 136, ittypically contains residual anions and cations which were not removed bythe mixed bed ion exchanger 124, along with traces of released sodiumions and chloride ions that were not removed by the mixed bed ionexchanger 126. It is to be understood that the intent is to have allanions and cations in the engine antifreeze coolant liquid removed bythe mixed bed ion exchanger 124 and to have all of the released sodiumand chloride ions removed by the mixed bed ion exchanger 126. However,one hundred percent (100%) removal is not guaranteed and traces ofanions and cations, along with traces of released sodium and chlorideions, may remain in the engine antifreeze coolant liquid exiting mixedbed ion exchanger 126 and passing into conduit 136 in the form ofresidual anions, residual cations, residual sodium ions and residualchloride ions. Some of the residual anions may include nitrite ions (NO₂⁻) which originates from sodium nitrite. Sodium nitrite is a compoundincluded within a corrosion inhibitor additive which previously had beenadded to the engine antifreeze coolant liquid to prevent corrosion ofthe metal of the engine cooling system (including the engine itself)from which the contaminated engine antifreeze coolant liquid wasremoved. Nitrite ions not removed by the strong acid cations exchangeresins in the Na⁺ form dispensed in the mixed bed ion exchanger 124, andpassing into contact with the strong acid cation exchange resins in theH⁺ form and positioned in the mixed bed ion exchanger 126, forms nitrousacid (HNO₂) with hydrogen ions released by the strong acid cationexchange resins in the H⁺ form. Nitrous acid decomposes into nitricoxide gas (NO) which in turn can combine with oxygen (O₂) to formnitrogen dioxide gas (NO₂). Oxygen is available to combine with nitricoxide from being entrained or otherwise contained in the water/aqueousphase of the engine antifreeze coolant liquid. The reactions andcombinations may be represented as follows: ##STR6## The nitrogencontaining compounds HNO₂, NO, and NO₂ are extremely deleterious. Thenitrogen containing gases NO and/or NO₂ are particularly extremelydeleterious, especially to human health. Thus, in a preferred embodimentof the present invention, the nitrogen containing compounds comprisingthe nitrogen-containing gas (i.e., NO and/or NO₂) are removed from theengine antifreeze coolant liquid in the zone for separating 134 whichreceives the engine antifreeze coolant liquid from the mixed bed ionexchanger 126.

The zone for separating 134 for the preferred embodiment of theinvention depicted in FIG. 21 may be any separating means (e.g. aseparator, etc.) which is capable of removing the nitrogen containingcompounds, particularly the gas(es) containing nitrogen, from the engineantifreeze coolant liquid. Preferably, the separating zone 134 is anysuitable nitrogen containing gas adsorber. More preferably, the nitrogencontaining gas adsorber comprises a filter container 150 havingactivated carbon particulate for filtering, trapping, or otherwiseremoving the nitrogen containing compounds. The activated carbonparticulates of this invention for the filter container 150 is anamorphous form of carbon characterized by high adsorptivity fornitrogen-containing gas, such as the NO and/or NO₂. The carbon isobtained by the destructive distillation of such carbonaceous materialsas animal bones, nut shells, and wood. The carbon is "activated" byheating at a temperature of 800° C. to 900° C. with steam and/or carbondioxide, resulting in an internal structure defined with porosity (i.e.,honeycomb-like). The internal surface area of the activated carbon forthe filter container 150 may be of any suitable particulate size, suchas having a surface area of from about 70 m² /g to about 2000 m² /g withan apparent density of from about 0.35 to about 0.65, and a mesh sizeranging from about 4×6 to about 28×34; more preferably, the activatedcarbon particulate has a surface area of from about 900 m² /g to about1100 m² /g with an apparent density of from about 0.44 to about 0.55 anda mesh size ranging from about 12×16 to about 20×24. Most preferably,the activated carbon particulate for filter container 150 has a surfacearea of about 1000 m² /g, an apparent density of about 0.49 and a meshsize of about 16×20. The most preferred activated carbon particulate forfilter container 150 may be purchased commercially from American NoritCo. Inc. under the trademark NORIT® RB-1. It has been discovered thatbest nitrogen gas adsorption from the engine antifreeze coolant liquidis obtained with employment of the most preferred activated carbonparticulate comprising a surface area of about 1000 m² /g, an apparentdensity of about 0.49 and a mesh size of about 16×20.

In a preferred embodiment of the present invention illustrated in FIGS.19, 22 and 23, the cation exchange bed ion exchanger 130 comprises aplurality of strong acid cation exchange resins 160 (see FIG. 14) in theH⁺ form. The anion exchange bed ion exchanger 132 comprises a pluralityof strong base anion exchange resins in the OH⁻ form. The preferredstrong acid cation exchange resins in the H⁺ form is a bead-form resinthat is commercially available as IONAC® C-249 from Sybron ChemicalsInc. IONAC® C-249 has a styrene divinylbenzene polymer structure with--SO₃ H functional groups. The strong base anion exchange resin in theOH⁻ form is preferably a bead-form resin that is commercially availableunder the trademark IONAC® ASB 2HP Type II from Sybron Chemicals Inc.IONAC ASB-2HP has a Type II styrene-divinylbenzene polymer structurewith a --CH₂ N(CH₃)₃ OH functional group.

In the preferred embodiment of the present invention depicted in FIGS.19, 22 and 23, contaminated engine antifreeze coolant liquid flowsthrough conduit 108, preferably at a flow rate of from about 1 gal. permin. to about 10 gals. per min., and into the cation exchange bed ionexchanger 130 where the strong acid cation exchange resins in the H⁺form removes at least some of the cations (e.g. calcium, magnesium,sodium, potassium, iron, manganese, copper, aluminum, mercury, barium,arsenic, lead, cadmium, silver, chromium, zinc, and hydronium, etc.)from the contaminated engine antifreeze coolant liquid while essentiallysimultaneously releasing thereinto their associated hydrogen ion (H⁺).After a residence time of from about 5 mins. to about 15 mins. in thecation exchange bed ion exchanger 130, the engine antifreeze coolantliquid (containing released hydrogen ions, anions, and perhaps someresidual cations which were not removed) leaves the cation exchange bedion exchanger 130 through conduit 128 and passes into the anion exchangebed ion exchanger 132, preferably at the same flow rate of from about 1gal. per min. to about 10 gal. per min. In the anion exchange bed ionexchanger 130, the strong base anion exchange resins in the OH⁻ formremoves at least some of the anions (e.g. chloride, sulfate, nitrate,carbonate, bicarbonate, silicate, fluoride, nitrite, sulfite, hydroxide,etc.) from the contaminated engine antifreeze coolant liquid whileessentially simultaneously releasing thereinto their associatedhydroxide ion (OH⁻). The hydrogen ions released in the cation exchangebed ion exchanger 130 and the hydroxide ions released in the anionexchange bed ion exchanger 132 combine to form water (H₂ O) whichbecomes part of the water/aqueous phase of the engine antifreeze coolantliquid. After a residence time of from about 5 mins. to about 15 mins.in the anion exchange bed ion exchanger 132, the engine antifreezecoolant liquid exits the anion exchange bed ion exchanger 132 and, forthe embodiment of the invention depicted in FIGS. 22 and 23, passes intothe separating zone/separator 134 via conduit 136.

In a further preferred embodiment of the present invention illustratedin FIGS. 19, 22 and 23, it is more preferred that in order to completelyde-ionize the engine antifreeze coolant liquid without additional ionexchange steps, it is essential that the hydrogen form of the cationresin 160 be used instead of the sodium form. Likewise, the hydroxideform of the anion resin is preferably used and not the chloride form.The hydrogen form of the cation exchange resin 160 releases hydrogenions as it removes cations from the effluent engine antifreeze coolantliquid. The hydroxide form of the anion exchange resin releaseshydroxide ions as it removes anions from the effluent engine antifreezecoolant liquid. Hydrogen ions combine with hydroxide ions to form water.The following diagram represents the reactions and combinations for H⁺and OH⁻ forms on cation/anion resins: ##STR7## with M⁺ representing apositively charged ion, X⁻ representing a negatively charged ion, and Psymbolizing the polymer support.

If the sodium and chloride forms of cation/anion resins were used in thefinal step of purification, a solution containing sodium chloride wouldbe obtained. Chloride ions, in particular, promote corrosion of metalsand must not be present in the final effluent if a Na⁺ /Cl⁻ free finaleffluent is desired. The following diagram represents the reactions andcombinations for the use of Na⁺ and Cl⁻ forms on cation/anion resins:##STR8## with M⁺ representing a positively charged ion, X⁻ representinga negatively charged ion, and P symbolizing the polymer support.Whenever the sodium/chloride forms of ion exchange cation/anion resinsare employed in the present invention, the effluent engine antifreezecoolant liquid must subsequently go through a third ion exchange processwith the hydrogen and hydroxide forms of cation/anion resins in order toremove Na⁺ and Cl⁻.

It is further preferred that when the H⁺ form and OH⁻ form of the cationresins and anion resins, respectively, are employed, the cation exchangebed ion exchanger 130 is to precede or be disposed in front of the anionexchange bed ion exchanger 132. If the engine antifreeze coolant liquidcontacts the anion exchange resin with the OH⁻ form before contactingthe cation exchange resin with the H⁺ form, the hydroxide ions releasedin anion exchange process would form insoluble hydroxide precipitates(e.g., Mg(OH)₂, Cu(OH)₂, Fe(OH)₃, Al(OH)₃, etc.), with many metalcations present in the engine antifreeze coolant liquid leaving theanion exchange bed ion exchanger 132. After the engine antifreezecoolant liquid enters the cation exchange bed ion exchanger 130, thesegelatinous precipitates would foul the cation resin 160 therein longbefore its capacity for removal of cations was reached. By running thecoolant solution through the cation exchange bed ion exchanger 130first, all metal cations are exchanged for hydrogen ions. Then in theanion exchange bed ion exchanger 132, these hydrogen ions react with thereleased hydroxide ions to produce water.

Many contaminated engine antifreeze coolant liquids contain nitritesalts, such as sodium nitrite, which is a compound that forms the basisfor a corrosion inhibitor additive, as previously indicated. When thecontaminated engine antifreeze coolant liquid enters into and is in thecation exchange bed ion exchanger 130 in FIGS. 19, 22 and 23, hydrogenions released off of the strong acid cation exchange resins 160 in theH⁺ form, combines with the nitrite ion to convert it into nitrous acid(HNO₂). At least some of the nitrous acid decomposes into nitric oxidegas (NO) before it is exchanged as nitrite in the anion exchange bed inexchanger 132. As previously indicated, nitric oxide gas can combinewith oxygen (O₂), which is available through entrainment in thewater/aqueous phase of the engine antifreeze coolant liquid, to formnitrogen dioxide gas (NO₂) The reactions and combinations may again berepresented as follows: ##STR9## The nitrogen containing compounds,especially the NO and/or NO₂, are removed to protect human health. Thisis the function of the separating zone/separator 134 illustrated inFIGS. 22 and 23, to remove the nitrogen containing compounds NO and/orNO₂ through trapping, or otherwise separating out, the NO and/or NO₂from the engine antifreeze coolant liquid exiting the anion exchange bedion exchanger 132. It is expected that the bulk of the nitrous acidand/or NO and/or NO₂ is formed in the cation exchange bed ion exchanger130 before passing through conduit 128 and into the anion exchange bedion exchanger 132. However, it is anticipated that nitrous acid and/orNO and/or NO₂ also forms in the conduit 128, the anion exchange bed ionexchanger 132, and in the conduit 136 leading from the anion exchangebed ion exchanger 132 to the separator/separating zone 134. The spiritand scope of the present invention encompasses the removal of thenitrogen containing compounds (NO and/or NO₂) by theseparator/separating zone 134 that were formed at any locale before theseparator/separating zone 134, including the cation exchange bed ionexchanger 130, the conduit 128, the anion exchange bed ion exchanger132, and the conduit 136.

The zone for separating/separator 134 for the preferred embodiment ofthe invention depicted in FIGS. 22 and 23 may be any suitable separatingmeans (e.g. a separator, etc.) which is capable of removing the nitrogencontaining compounds, particularly the gas(es) containing nitrogen, fromthe engine antifreeze coolant liquid. Preferably, the separating zone134 in FIGS. 22 and 23 is any suitable nitrogen-containing gas adsorber.More preferably, the nitrogen containing gas adsorber comprises thefilter container 150 of FIG. 21 having activated carbon particulate forfiltering, trapping, or otherwise removing the nitrogen containingcompounds. The activated carbon particulate of this invention for thefilter container 150 in FIGS. 22 and 23 is essentially an amorphous formof carbon characterized by high adsorptivity for nitrogen-containinggas, such as the NO and/or NO₂. The carbon is obtained by thedestructive distillation of such carbonaceous materials as animal bones,nut shells, and wood. The carbon is "activated" as the carbon incontainer 150 of FIG. 21 by heating at a temperature of 800° C. to 900°C. with steam and/or carbon dioxide, resulting in an internal structuredefined with porosity (i.e., honeycomb-like). The internal surface areaof the activated carbon for the filter container 150 in FIGS. 22 and 23may be of any suitable particulate size, such as having a surface areaof from about 70 m² /g to about 2000 m² /g with an apparent density offrom about 0.35 to about 0.65, and a mesh size (U.S. Sieve Series)ranging from about 4×6 to about 28×34; more preferably, the activatedcarbon particulate for the embodiment of the invention in FIGS. 22 and23 is a particulate activated carbon bought commercially under thetrademark NORIT® owned by the American Norit Co. Inc., such as NORIT® RB1, NORIT® RB 2, NORIT® RB 3, and NORIT® RB 4 which respectively have theproperties listed in the following TABLE I:

    ______________________________________                                        TYPICAL                                                                       ANALYSIS     RB 1     RB 2     RB 3   RB 4                                    ______________________________________                                        Apparent density,                                                                          .490     .490     .460   .460                                    g/ml                                                                          Moisture, % as packed                                                                      2.0      2.0      2.0    2.0                                     Ash, %       6.0      6.0      6.0    6.0                                     Hardness (ASTM)                                                                            99       99       99     99                                      Ignition temp.                                                                             450      450      450    450                                     (ASTM), °C.                                                            Pore size distribution,                                                       ml/g:                                                                         micropores   0.36     0.36     0.36   0.36                                    (less than 1 nm)                                                              transitional pores                                                                         0.08     0.08     0.08   0.08                                    (1-100 nm)                                                                    macropores   0.41     0.41     0.41   0.41                                    (greater than 100 nm)                                                         Surface area 1000     1000     1000   1000                                    (N.sub.2 -BET), m.sup.2 /g                                                    Pellet diameter, nm                                                                        1.0      2.0      2.9    3.8                                     Corresponding mesh                                                                         16 × 20                                                                           8 × 12                                                                          6 × 8                                                                          4 × 6                             size, U.S. Sieve Series                                                       ______________________________________                                    

In a preferred embodiment of the invention, the most preferred activatedcarbon particulate for filter container 150 in FIGS. 22 and 23 is thatpurchased commercially from American Norit Co. Inc. under the trademarkNORIT® RB-1. It has been discovered that for the preferred embodiment ofthe invention in FIGS. 22 and 23, the best adsorption of nitrogen gasfrom the engine antifreeze coolant liquid is obtained with employment ofthe most preferred activated carbon particulate comprising a surfacearea of about 1000 m² /g, an apparent density of about 0.49 and a meshsize of about 16×20.

As was seen for the preferred embodiment of the invention depicted inFIG. 21, it is intended that all of the anions and cations in the enginecoolant liquid for the preferred embodiment of the invention in FIGS.19, 22 and 23 are removed by cation exchange bed ion exchanger 130 andanion exchange bed ion exchanger 132 by a single passage through theapparatus 10; and that all of the nitrogen containing compounds (i.e.,NO and/or NO₂) are removed by adsorber/separator 134 for the preferredembodiment of the invention in FIGS. 22 and 23 also by a single passagethrough the apparatus 10. However, one hundred percent (100%) removal ofthese constituents are not guaranteed, and traces of anions, cations andnitrogen containing compounds may remain in the purified engineantifreeze coolant liquid after a single pass through the apparatus 10.Therefore, optionally, the purified engine antifreeze coolant liquid maybe recycled through the apparatus 10 again to ensure a more completepurification. Thus, the spirit and scope of the present invention forthe preferred embodiment of the invention illustrated in FIGS. 19, 22and 23 includes recycling the purified engine antifreeze coolant liquidas many times as necessary to ensure complete purification.

With continuing reference to the drawings for operation of the presentinvention, any suction hose (such as conduit 58) is connected or engagedto inlet conduit 50 at connection 53 and is placed in communication withcontaminated engine antifreeze coolant liquid such as by inserting intoa drum (not shown) containing the contaminated engine antifreeze coolantliquid or by connecting to an engine cooling system at connection 54.The contaminated engine antifreeze coolant liquid has particulates,hydrocarbons, anions and cations, all of which are to be removed by theapparatus 10. Clamps 36--36 are engaged to a DC power source, such asbattery 40. Switch 32 is turned to an "on" position which energizes pump78 to start the intake or flow (at 1 to 10 gal. per in.) of contaminatedengine antifreeze coolant liquid into inlet conduit 50 and through valve76, through pump 78, and into communication with pressure gauge 34 whichdisplays a certain pressure. A displayed high pressure (e.g. greaterthan 70 psi) indicates that there is a blockage downstream, such as inthe filtering zone 80 or in the ion exchange zone 110. A normal pressure(e.g. 35 psi) indicates that there is no blockage downstream (i.e.,between pressure gauge 34 and connection 74). For the embodiment of theinvention illustrated in FIGS. 19 and 21, from communication withpressure gauge 34 in inlet conduit 50, contaminated engine antifreezecoolant liquid enters into the filtering zone 80, more specifically itpasses through inlet filter conduit 96 and into mechanical filter 82where any larger particulates, such as 25 microns or larger, areremoved. From the mechanical filter 82, the contaminated engineantifreeze coolant liquid passes through outlet filter conduit 98 andinto the chemical filter 84 where hydrocarbons (and any other chemicalsand contaminating liquids, except water and ethylene glycol) areremoved. Typical hydrocarbons that are removed in chemical filter 84 aregrease, oil, etc. From chemical filter 84, the contaminated engineantifreeze coolant liquid passes through inlet filter conduit 96 andinto mechanical filter 86 where the smaller particulates (such as 5microns or larger) are removed. From the mechanical filter 86,filtered/contaminated engine antifreeze coolant liquid passes throughoutlet filter conduit 98 and into intermediate conduit 108.

In the preferred embodiment of the invention depicted in FIG. 23, thefiltering zone 80 is split such that mechanical filter 82 precedes thepump 78 and pressure gauge 34, and chemical filter 84 and mechanicalfilter 86 follows the pump 78 and pressure gauge 34. In this preferredembodiment of the invention, the larger particulates (e.g. 25 microns orlarger) are removed from the contaminated engine antifreeze coolantliquid in mechanical filter 82 before the contaminated engine antifreezecoolant liquid passes through pump 78 to prevent gross particulates fromentering the pump 78 and damaging it. After the larger particulates havebeen removed from the contaminated engine antifreeze coolant liquid, thecontaminated engine antifreeze coolant liquid passes through the pump 78and into communication with the pressure gauge 34 and subsequently intothe chemical filter 84 for removal of the hydrocarbons (i.e., oil,grease, etc.). From the chemical filter 84, the contaminated engineantifreeze coolant liquid passes through inlet filter conduit 96 andinto the mechanical filter 86 where, as previously indicated, smallerparticulates are removed. After essentially all of the desired sizeparticulates (e.g. 5 microns or larger) and essentially all of thehydrocarbons have been removed by the filtering zone 80, the engineantifreeze coolant liquid passes through outlet filter conduit 98 andinto the intermediate conduit 108 for transport therein to the ionexchange zone 108 for removal of the cations and the anions.

In the preferred embodiment of the ion exchange zone 108 depicted inFIGS. 19, 22 and 23, contaminated engine antifreeze coolant liquidflows, preferably at a flow rate of from about 1 gal. per min. to about10 gal. per min., into the strong acid cation exchanger 130 containingstrong acid cation exchange resins 160 in the H⁺ form which removeessentially all of the cations (e.g. calcium, sodium, potassium, etc.)from the contaminated engine antifreeze coolant liquid, while, generallyat the same time, releases associated hydrogen ion (H⁺) into thecontaminated engine antifreeze coolant liquid. After a preferredresidence time of from about 5 mins. to about 15 mins. in the cationexchange bed ion exchanger 130, the contaminated engine antifreezecoolant liquid leaves the cation exchange bed ion exchanger 130 throughconduit 128 for discharge into the anion exchange bed ion exchanger 132containing strong base anion exchange resins OH⁻ form. When thecontaminated engine antifreeze coolant liquid leaves the cation exchangebed ion exchanger 132, it contains released hydrogen ions, anions, andnitrogen containing compounds such as HNO₂ and/or NO and/or NO₂ Thesenitrogen containing compounds formulated as a result of releasedhydrogen ions combining with NO₂ ⁻ to produce nitrous acid (HNO₂) whichin turn decomposes into nitric oxide (NO). As previously indicated,nitric oxide can combine and/or react with oxygen entrained in theengine antifreeze coolant liquid to produce nitrogen dioxide (NO₂).

In the anion exchange bed ion exchanger 132, the strong base anionexchange resins in the OH⁻ form removes essentially all of the anions(e.g. chloride, nitrate, nitrite, etc.) from the contaminated engineantifreeze coolant liquid, while, generally at the same time, releasesassociated hydroxide ion (OH⁻) into the contaminated engine antifreezecoolant liquid. The released hydroxide ions combine with the hydrogenions previously released by the strong acid cation exchange resins 160to form water. The residence time for the contaminated engine antifreezecoolant liquid in the anion exchange bed ion exchanger 132 is preferablyfrom about 5 mins. to about 15 mins. The contaminated engine antifreezecoolant liquid leaves the anion exchange bed ion exchanger 132 throughconduit 136 and contains the nitrogen containing compounds. For thepreferred embodiment of the invention depicted in FIGS. 22 and 23, thecontaminated engine antifreeze coolant liquid passes from the anionexchange bed ion exchanger 132 via conduit 136 into the separatingzone/separator 1334 where the hydrogen containing compounds (moreparticularly NO and/or NO₂) are removed. After a residence time of fromabout 5 mins. to about 15 mins. in the separating zone/separator 134,the engine antifreeze coolant liquid leaves the separationzone/separator 134 as a purified engine antifreeze coolant liquid, andpasses into outlet conduit 52 and flows therein through the sensoringzone 112 wherein the resistivity and/or conductivity of the purifiedengine antifreeze coolant liquid is being monitored and/or measured, asan indicator of the ion-removal effectiveness by the ion exchange zone110 and as a measure of the degree of the purification of the engineantifreeze coolant liquid. After the degree of purification of thepurified engine antifreeze coolant liquid has been monitored and/ordetermined and the indicator light 42 did not light, the purified engineantifreeze coolant liquid flows through electronic valve 114 andcontinues to flow through outlet conduit 52 for discharge at connection74. If the indicator light 42 lights, the operator should investigatethe ion exchange zone 110 and replace and/or replenish the same, such asremoval and replacement of the exhausted cation exchange bed ionexchanger 130 and/or the exhausted anion exchange bed ion exchanger 132.It is intended that the purified engine antifreeze coolant liquid hasbeen sufficiently purified after one (1) single pass through theinternals of the apparatus 10. After the engine antifreeze coolantliquid has obtained sufficient purification, it should be essentiallyclear, having essentially only ethylene glycol and water.

Inhibitors and additives have to be added to the purified engineantifreeze coolant liquid to protect any cooling system of any enginewhich is to come in contact with the purified engine antifreeze coolantliquid. To the purified engine antifreeze coolant liquid, a yellowinhibitor mixture and a blue inhibitor mixture are added. When bothmixtures are added, preferably in equal parts, the purified and treatedengine antifreeze coolant liquid will be blue green, indicating thatboth mixtures of additives and inhibitors were indeed added and that thepurified engine antifreeze coolant liquid has been sufficiently treatedwith additives and inhibitors.

Thus, by the practice of this invention there is provided an apparatusand method for removing particulates, hydrocarbons, cations, anions, andnitrogen containing compounds (produced in the cation exchange bed inexchanger 130), from a contaminated engine antifreeze coolant liquid.The apparatus and method of the present invention has the capability oftaking even the dirtiest, most contaminated, used engine antifreezecoolant liquid, purifying it and replacing the used inhibitors andreturning it to service. The resulting purified and treated entineantifreeze coolant liquid is formulated to meet the general/performancerequirements of ASTM D3306, standard specification for ethylene glycolbase engine coolant, a concentrated antifreeze.

While the present invention has been described herein with reference toparticular embodiments thereof, a latitude of modification, variouschanges and substitutions are intended in the foregoing disclosure, andit will be appreciated that in some instances some features of theinvention will be employed without a corresponding use of other featureswithout departing from the scope of the invention as set forth.

We claim:
 1. A method for removing ions from a liquid comprising thesteps of:(a) passing a liquid having ions, including nitrite ions,through a cation exchanger bed wherein at least part of the ions areremoved and at least part of the nitrite ions is converted into nitrogencontaining compounds selected from the group consisting of nitrous acid,nitric oxide, nitrogen dioxide, and mixtures thereof, to produce aliquid with at least part of the ions removed and having nitrogencontaining compounds; and (b) removing at least part of the nitrogencontaining compounds selected from the group consisting of nitrous acid,nitric oxide, nitrogen dioxide, and mixtures thereof, by passing theproduced liquid of step (a) through a means for removing nitrogencontaining compounds to produce a liquid with at least part of the ionsremoved and with at least part of the nitrogen containing compoundsremoved.
 2. The method of claim 1 wherein said liquid is an enginecoolant liquid.
 3. The method of claim 2 wherein said means for removingnitrogen containing compounds comprises activated carbon particulatehaving a surface area of about 1000 m² /g with an apparent density ofabout 0.49 and a mesh size of about 16×20.
 4. The method of claim 1additionally comprising passing, prior to said passing step (a), theliquid through a means for filtering.
 5. The method of claim 1additionally comprising passing, prior to said passing step (b), theproduced liquid of step (a) through an anion exchanger bed.
 6. Themethod of claim 1 additionally comprising passing, prior to said passingstep (a), the liquid through a first means for filtering; passingsubsequently, prior to said passing step (a), the liquid from the firstmeans for filtering through a means for pumping wherein the liquid fromthe first means for filtering is pumped towards a second means forfiltering; and passing subsequently thereafter, prior to said passingstep (a), the liquid from the means for pumping through a second meansfor filtering.
 7. The method of claim 1 additionally comprising passingthe produced liquid of step (b) through a sensoring means to monitor theresistivity or conductivity of the liquid as a measure of a degree ofpurification of the liquid.
 8. The method of claim 1 additionallycomprising adding to the liquid a first mixture having a first color;adding to the liquid a second mixture having a second color which isdifferent from the first color to produce a third color in the liquidwhich is different from the first color and the second color.
 9. Themethod of claim 1 where said means for removing nitrogen containingcompounds comprises activated carbon particulate having a surface areaof from about 900 m² /g to about 1100 m² /g with an apparent density offrom about 0.44 to about 0.55.
 10. The method of claim 9 wherein saidactivated carbon particulate additionally includes a mesh size rangingfrom about 12×16 to about 20×24.
 11. A method for removing cations andanions from a liquid comprising the steps of:(a) providing a liquidhaving cations, anions, and nitrite ions; (b) passing the liquid of step(a) through a cation-exchanger bed wherein at least part of the cationsare removed and at least part of the nitrite ions is converted intonitrogen containing compounds selected from the group consisting ofnitrous acid, nitric oxide, nitrogen dioxide, and mixtures thereof, toproduce a liquid containing anions and nitrogen containing compoundsselected from the group consisting of nitrous acid, nitric oxide,nitrogen dioxide, and mixtures thereof; (c) passing the produced liquidof step (b) through an anion-exchanger bed wherein at least part of theanions are removed to produce a liquid containing nitrogen containingcompounds selected from the group consisting of nitrous acid, nitricoxide, nitrogen dioxide, and mixtures thereof; and (d) removing at leastpart of the nitrogen containing compounds selected from the groupconsisting of nitrous acid, nitric oxide, nitrogen dioxide, and mixturesthereof, by passing the produced liquid of step (c) through a means forseparating wherein at least part of the nitrogen containing compounds isremoved from the liquid.
 12. The method of claim 11 wherein said liquidof step (a) is an engine coolant liquid.
 13. The method of claim 12wherein said engine coolant liquid of step (a) contains a freezing pointdepressant; and said produced liquid of step (c) contains said freezingpoint depressant.
 14. The method of claim 13 wherein said means forseparating of step (d) produces an engine coolant liquid having at leastpart of the nitrogen containing compound removed and the freezing pointdepressant.
 15. The method of claim 13 wherein said means for separatingcomprises activated carbon particulate having a surface area of about1000 m² /g with an apparent density of about 0.49 and a mesh size ofabout 16×20.
 16. The method of claim 11 additionally comprising passing,prior to said passing step (b), the liquid of step (a) through a meansfor filtering.
 17. The method of claim 16 wherein said means forfiltering comprises a chemical filter and a mechanical filtercommunicating with the chemical filter.
 18. The method of claim 11additionally comprising passing, prior to said passing step (b), theliquid of step (a) through a first means for filtering; passingsubsequently, prior to said passing step (b), the liquid from the firstmeans for filtering through a means for pumping wherein the liquid ofstep (a) from the first means for filtering is pumped towards a secondmeans for filtering; and passing subsequently thereafter, prior to saidpassing step (b), the liquid from the means for pumping through a secondmeans for filtering.
 19. The method of claim 18 wherein said secondmeans for filtering comprises a chemical filter and a mechanical filtercommunicating with the chemical filter.
 20. The method of claim 11wherein said providing step (a) comprises removing said liquid of step(a) from a cooling system of an internal combustion engine to theexterior of said internal combustion engine; and returning, after saidpassing step (d), the liquid to the cooling system of the internalcombustion engine, wherein said returning liquid has at least part ofthe cations and anions removed and at least part of the nitrogencontaining compounds removed.
 21. The method of claim 20 wherein saidliquid is an engine coolant liquid containing a freezing pointdepressant; and said liquid returning to the cooling system of theinternal combustion engine contains said freezing point depressant. 22.The method of claim 8 wherein said means for separating comprisesactivated carbon particulate having a surface area of from about 900 m²/g to about 1100 m² /g with an apparent density of from about 0.44 toabout 0.55.
 23. The method of claim 22 wherein said activated carbonparticulate additionally includes a mesh size ranging from about 12×16to about 20×24.
 24. A method for removing particulates, cations, anionsand nitrogen containing compounds from an engine coolant liquidcomprising the steps of:(a) providing an engine coolant havingparticulates, cations, anions and nitrite ions; (b) passing the enginecoolant liquid of step (a) through a means for filtering wherein atleast part of the particulates are removed from the engine coolantliquid to produce an engine coolant liquid comprising cations, anionsand nitrite ions; (c) passing the produced engine coolant liquid of step(b) through a cation exchanger bed wherein at least part of the cationsis removed and at least part of the nitrite ions is converted intonitrogen containing compounds selected from the group consisting ofnitrous acid, nitric oxide, nitrogen dioxide, and mixtures thereof, toproduce an engine coolant liquid containing anions and nitrogencontaining compounds; (d) passing the produced engine coolant liquid ofstep (c) through an anion-exchanger bed wherein at least part of theanions is removed to produce an engine coolant liquid containingnitrogen containing compounds selected from the group consisting ofnitrous acid, nitric oxide, nitrogen dioxide, and mixtures thereof; and(e) removing at least part of the nitrogen containing compounds selectedfrom the group consisting of nitrous acid, nitric oxide, nitrogendioxide, and mixtures thereof, by passing the produced engine coolantliquid of step (d) through a means for separating wherein at least partof the nitrogen containing compounds is removed from the engine coolantliquid.
 25. The method of claim 25 wherein said engine coolant liquid ofstep (a) contains a freezing point depressant; and said engine coolantliquid returning to the cooling system of the internal combustion enginecontains said freezing point depressant.
 26. The method of claim 24wherein said providing step (a) comprises removing said engine coolantliquid of step (a) from a cooling system of an internal combustionengine to the exterior of said internal combustion engine; andreturning, after said passing step (e), the engine coolant liquid to thecooling system of the internal combustion engine, wherein said returningengine coolant liquid has at least part of the particulates, thecations, and the anions removed and at least part of the nitrogencontaining compounds removed.
 27. The method of claim 24 where saidmeans for separating comprises activated carbon particulate having asurface area of from about 900 m² /g to about 1100 m² /g with anapparent density of from about 0.44 to about 0.55.
 28. The method ofclaim 27 wherein said activated carbon particulate additionally includesa mesh size ranging from about 12×16 to about 20×24.
 29. A method forremoving particulates, cations, anions, and nitrogen containingcompounds from an engine coolant liquid comprising the steps of:(a)providing an engine coolant having particulates, cations, anions andnitrite ions; (b) passing the engine coolant liquid of step (a) througha means for filtering wherein at least part of the particulates areremoved from the engine coolant liquid to produce an engine coolantliquid comprising cations, anions and nitrite ions; (c) passing theproduced engine coolant liquid of step (b) through a strong acid cationexchanger bed in the hydrogen form wherein at least part of the cationsis removed and at least part of the nitrite ions is converted intonitrous acid; (d) passing the produced engine coolant liquid from thestrong acid cation exchanger bed through a strong base anion-exchangerbed in the hydroxide form wherein at least part of the anions isremoved, said nitrous acid produced in the strong cation exchanger beddecomposes into nitric oxide which combines with oxygen to form nitrogendioxide such that said strong base anion exchanger bed produces anengine coolant liquid containing nitrogen dioxide; and (e) removing atleast part of the nitrogen dioxide from the produced engine coolantliquid by passing the produced engine coolant liquid of step (d) througha means for separating wherein at least part of the nitrogen dioxide isremoved from the engine coolant liquid.
 30. The method of claim 29wherein engine coolant liquid of step (a) contains a freezing pointdepressant; and said produced engine coolant liquid of step (d) containssaid freezing point depressant.
 31. The method of claim 30 wherein saidmeans for separating of step (e) produces an engine coolant liquidhaving at least part of the nitrogen gas removed and the freezing pointdepressant.
 32. The method of claim 29 wherein said means for filteringcomprises at least one mechanical filter and a chemical filter.
 33. Themethod of claim 32 additionally comprising a means for pumping enginecoolant liquid, and a first mechanical filter for receiving the enginecoolant liquid of step (a) and in communication with said means forpumping, and said chemical filter is in communication with said meansfor pumping for receiving engine coolant liquid from the means forpumping and a second mechanical filter is in communication with saidchemical filter, said method further additionally comprises passingprior to said passing step (c) the engine coolant liquid of step (a)through the first mechanical filter to remove particulates; passingsubsequently prior to said passing step (c) the engine coolant liquidfrom the first mechanical filter to the means for pumping where theengine coolant liquid is pumped towards the chemical filter; passingprior to said passing step (c) the pumped engine coolant liquid throughthe chemical filter; and passing subsequently prior to said passing step(c) the engine coolant liquid from the chemical filter through thesecond mechanical filter for removal of particulates.
 34. The method ofclaim 29 wherein said means for separating comprises activatedparticulate carbon.
 35. The method of claim 29 wherein said providingstep (a) comprises removing said engine coolant liquid of step (a) froma cooling system of an internal combustion engine to the exterior ofsaid internal combustion engine; and returning, after said passing step(e), the engine coolant liquid to the cooling system of the internalcombustion engine, wherein said returning engine coolant liquid has atleast part of the particulates, the cations, and the anions removed andat least part of the nitrogen dioxide removed.
 36. The method of claim35 wherein said engine coolant liquid of step (a) contains a freezingpoint depressant; and said engine coolant liquid returning to thecooling system of the internal combustion engine contains said freezingpoint depressant.
 37. The method of claim 29 additionally comprisingpassing, prior to said passing step (b), the engine coolant liquidthrough a heat exchanger means for cooling the engine coolant liquid.38. The method of claim 29 where said means for separating comprisesactivated carbon particulate having a surface area of from about 900 m²/g to about 1100 m² /g with an apparent density of from about 0.44 toabout 0.55.
 39. The method of claim 38 wherein said activated carbonparticulate additionally includes a mesh size ranging from about 12×16to about 20×24.
 40. The method of claim 29 wherein said means forseparating comprises activated carbon particulate having a surface areaof about 1000 m² /g with an apparent density of about 0.49 and a meshsize of about 16×20.
 41. A method for removing cations and anions froman engine coolant liquid having a freezing point depressant and situatedin a cooling system of an internal combustion engine, comprising thesteps of:(a) removing an engine coolant liquid having cations, anions,particulates, hydrocarbons, and a freezing point depressant and situatedin an internal combustion engine, from a cooling system of said internalcombustion engine to the exterior of said internal combustion engine;(b) passing the engine coolant liquid through a first mechanical filterfor filtering and removing part of the particulates, leaving residualparticulates in the engine coolant liquid; (c) passing the enginecoolant liquid having the residual particulates through a means forpumping wherein the engine coolant liquid is pumped; (d) passing thepumped engine coolant liquid through a chemical filter wherein at leastpart of the hydrocarbons is removed; (e) passing the engine coolantliquid having at least part of the hydrocarbons removed through a secondmechanical filter for filtering and removing at least part of theresidual particulates to produce engine coolant liquid having cations,anions, and the freezing point depressant; (f) passing the enginecoolant liquid, having the cations and the anions and the freezing pointdepressant, through a cation-exchanger bed wherein at least part of thecations are removed from the engine coolant liquid; (g) passing theengine coolant liquid, having at least part of the cations removed andhaving the anions and the freezing point depressant, through ananion-exchanger bed wherein at least part of the anions are removed fromthe engine coolant liquid; and (h) returning the engine coolant liquidto the cooling system of the internal combustion engine, wherein saidreturning engine coolant liquid has at least part of the cations andanions removed and has the freezing point depressant.
 42. The method ofclaim 41 wherein said engine coolant liquid from the anion-exchanger bedadditionally comprises a nitrogen containing compound selected from thegroup consisting of nitrous acid, nitric oxide, nitrogen dioxide, andmixtures thereof.
 43. The method of claim 42 additionally comprisingremoving, prior to said returning step (h), the nitrogen containingcompound from the engine coolant liquid.
 44. The method of claim 41additionally comprising passing prior to step (b) the engine coolantliquid of step (a) through a heat exchanger.
 45. The method of claim 44additionally comprising detecting, prior to step (d) and after step (c),the pressure of the pumped engine coolant liquid.
 46. The method ofclaim 45 additionally comprising passing, prior to step (h), the enginecoolant liquid through a means for sensoring for monitoring theresistivity or conductivity of the engine coolant liquid as a measure ofa degree of purification of the engine coolant liquid.
 47. A method forremoving particulates, hydrocarbons, cations, anions and nitrite ionsfrom an engine coolant liquid having a freezing point depressantcomprising the steps of:(a) providing an engine coolant havingparticulates, hydrocarbons, cations, anions and nitrite ions, and afreezing point depressant; (b) passing the engine coolant liquid of step(a) through a first mechanical filtering means for filtering and whereinpart of the particulates are removed to produce an engine coolant liquidhaving residual particulates, hydrocarbons, cations, anions, nitriteions, and the freezing point depressant; (c) passing the produced enginecoolant liquid of step (b) through a means for pumping wherein theproduced engine coolant liquid of step (b) is pumped towards a chemicalfiltering means for filtering and wherein at least part of thehydrocarbons is to be removed; (d) passing the pumped engine coolantliquid of step (c) through a chemical filtering means for filtering andwherein at least part of the hydrocarbons is removed to produced anengine coolant liquid having residual particulates, cations, anions,nitrite ions and the freezing point depressant; (e) passing the producedengine coolant liquid of step (c) through a second mechanical filteringmeans for filtering and wherein at least part of the residualparticulates is removed to produce an engine coolant liquid havingcations, anions, nitrite ions, and the freezing point depressant; (f)passing the produced engine coolant liquid of step (e) through a strongacid cation exchange bed in the hydrogen form wherein at least part ofthe cations is removed and at least part of the nitrite ions isconverted into a gas containing nitrogen and selected from the groupconsisting of nitric oxide, nitrogen dioxide, and mixtures thereof, toproduce an engine coolant liquid having anions, the gas containingnitrogen, and the freezing point depressant; (g) passing the producedengine coolant liquid of step (f) through a strong base anion exchangebed in the hydroxide form wherein at least part of the anions is removedto produce an engine coolant liquid having the gas containing nitrogenand the freezing point depressant; and (h) removing at least art of thegas containing nitrogen by passing the produced engine coolant liquid ofstep (g) through a bed of activated particulate carbon wherein at leastpart of the gas containing nitrogen is removed to produce an enginecoolant liquid having the freezing point depressant.
 48. The method ofclaim 47 wherein said chemical filtering means comprises a mechanicalfilter surrounded by activated carbon particulates.
 49. The method ofclaim 47 where said activated particulate carbon comprises a surfacearea of from about 900 m² /g to about 1100 m² /g with an apparentdensity of from about 0.44 to about 0.55.
 50. The method of claim 49wherein said activated particulate carbon additionally includes a meshsize ranging from about 12×16 to about 20×24.
 51. A method for removingparticulates, hydrocarbons, cations, anions and nitrite ions from anengine coolant liquid having a freezing point depressant comprising thesteps of:(a) providing an engine coolant liquid having particulates,hydrocarbons, cations, anions and nitrite ions, and a freezing pointdepressant; (b) passing the engine coolant liquid of step (a) through ameans for pumping wherein the engine coolant liquid of step (a) ispumped towards a first mechanical filtering means for filtering; (c)passing the engine coolant liquid of step (b) through a first mechanicalfiltering means for filtering and wherein part of the particulates areremoved to produce an engine coolant liquid having residualparticulates, hydrocarbons, cations, anions, nitrite ions, and thefreezing point depressant; (d) passing the engine coolant liquid of step(c) through a chemical filtering means for filtering and wherein atleast part of the hydrocarbons is removed to produce an engine coolantliquid having residual particulates, cations, anions, nitrite ions andthe freezing point depressant; (e) passing the produced engine coolantliquid of step (d) through a second mechanical filtering means forfiltering and wherein at least part of the residual particulates isremoved to produce an engine coolant liquid having cations, anions,nitrite ions, and the freezing point depressant; (f) passing theproduced engine coolant liquid of step (e) through a strong acid cationexchange bed in the hydrogen form wherein at least part of the cationsis removed and at least part of the nitrite ions is converted into a gascontaining nitrogen and selected from the group consisting of nitricoxide, nitrogen dioxide, and mixtures thereof, to produce an enginecoolant liquid having anions, the gas containing nitrogen, and thefreezing point depressant; (g) passing the produced engine coolantliquid of step (f) through a strong base anion exchange bed in thehydroxide form wherein at least part of the anions is removed to producean engine coolant liquid having the gas containing nitrogen and thefreezing point depressant; and (h) passing the produced engine coolantliquid of step (g) through a bed of activated particulate carbon whereinat least part of the gas containing nitrogen is removed to produce anengine coolant liquid having the freezing point depressant.
 52. A methodfor removing particulates, hydrocarbons, cations, anions and nitriteions from an engine coolant liquid comprising the steps of:(a) providingan engine coolant liquid having particulates, hydrocarbons, cations,anions and nitrite ions; (b) passing the provided engine coolant liquidof step (a) through a means for pumping wherein the provided enginecoolant liquid of step (a) is pumped towards a first mechanicalfiltering means for filtering; (c) passing the engine coolant liquid ofstep (b) through a first mechanical filtering means for filtering andwherein part of the particulates are removed to produce an enginecoolant liquid having residual particulates, hydrocarbons, cations,anions, nitrite ions; (d) passing the engine coolant liquid of step (c)through a chemical filtering means for filtering and wherein at leastpart of the hydrocarbons is removed to produce an engine coolant liquidhaving residual particulates, cations, anions, and nitrite ions; (e)passing the produced engine coolant liquid of step (d) through a secondmechanical filtering means for filtering and wherein at least part ofthe residual particulates is removed to produce an engine coolant liquidhaving cations, anions, and nitrite ions; (f) passing the producedengine coolant liquid of step (e) through a strong acid cation exchangebed in the hydrogen form wherein at least part of the cations is removedand at least part of the nitrite ions is converted into a gas containingnitrogen and selected from the group consisting of nitric oxide,nitrogen dioxide, and mixtures thereof, to produce an engine coolantliquid having anions, the gas containing nitrogen; (g) passing theproduced engine coolant liquid of step (f) through a strong base anionexchange bed in the hydroxide form wherein at least part of the anionsis removed to produce an engine coolant liquid having the gas containingnitrogen; (h) removing at least part of the gas containing nitrogen andselected from the group consisting of nitric oxide, nitrogen dioxide,and mixtures thereof by passing the produced engine coolant liquid ofstep (g) through a bed of activated particulate carbon wherein at leastpart of the gas containing nitrogen is removed.